All The Claims

1. A method for making a semiconductor structure, comprising:
providing a donor wafer comprising:
a silicon layer that has relaxed strain;
a graded silicon germanium (SiGe) layer on the silicon layer; and
a SiGe buffer layer on the graded SiGe layer, wherein the SiGe buffer layer has relaxed strain;

epitaxially growing a first silicon layer on the SiGe buffer layer to have tensile strain;
forming a first dielectric layer on the first silicon layer;
performing an implant to form a cleave line in the SiGe buffer layer;
providing a handle wafer comprising:
a semiconductor substrate; and
second dielectric layer on the semiconductor substrate;

bonding the second dielectric layer to the first dielectric layer;
cleaving the SiGe buffer layer along the cleave line to leave the first dielectric layer, the first silicon layer, and a portion of the SiGe buffer layer attached to the handle wafer;
removing the portion of the SiGe layer to expose the first silicon layer;
epitaxially growing silicon on the first silicon layer by applying trisilane at a temperature below 650 degrees Celsius to form a low temperature silicon layer on the first silicon layer, wherein the low temperature silicon layer has tensile strain.
2. The method of claim 1, further comprising forming a transistor having a gate over the low temperature silicon layer, a first sourcedrain in the low temperature silicon layer, and a second sourcedrain in the low temperature in the low temperature silicon layer, wherein the gate is over a space between the first and second sourcedrains.
3. The method of claim 1, wherein the step of epitaxially growing silicon forms the low temperature silicon layer to a thickness of at least three times thicker than the first silicon layer and with biaxial tensile strain.
4. The method of claim 1, wherein the step of epitaxially growing silicon further comprises applying hydrogen with the trisilane.
5. The method of claim 1, wherein the step of epitaxially growing silicon further comprises applying helium with the trisilane.
6. The method of claim 1, wherein the step of providing the donor wafer is further characterized as providing the buffer SiGE layer at a germanium concentration of at least 30 percent.
7. The method of claim 6, wherein:
the step of epitaxially growing the first silicon layer grows the first silicon layer to a thickness less than 200 Angstroms; and
the step of epitaxially growing silicon forms the low temperature silicon layer to a thickness in excess of 300 Angstroms.
8. The method of claim 7, wherein the step of epitaxially growing silicon forms the low temperature silicon layer to a thickness in excess of 500 Angstroms.
9. The method of claim 8, wherein the step of epitaxially growing silicon forms the low temperature silicon layer to a thickness of about 1000 Angstroms.
10. The method of claim 1, wherein the forming the first dielectric layer comprises forming the first dielectric layer of high temperature oxide formed from dichlorosilane and nitrous oxide at a temperature of at least 750 degrees Celsius.
11. The method of claim 1, wherein the forming the first dielectric layer comprises forming the first dielectric layer of high temperature oxide formed from disilane and nitrous oxide at a temperature between about 800 and 850 degrees Celsius.
12. The method of claim 1, wherein the step of epitaxially growing the low temperature silicon layer is performed at a temperature not greater than 500 degrees Celsius.
13. A method of forming a semiconductor structure, comprising:
providing a donor wafer comprising:
a silicon layer;
a graded silicon germanium (SiGE) layer on the silicon layer; and
a SiGe buffer layer on the graded SiGe layer;

epitaxially growing a first silicon layer on the SiGe buffer layer;
forming a first dielectric layer on the first silicon layer;
providing a handle wafer comprising:
a supporting substrate; and
second dielectric layer on the supporting substrate;

bonding the second dielectric layer to the first dielectric layer;
cleaving the SiGe buffer layer to leave the first dielectric layer, the silicon layer, and a portion of the SiGe buffer layer attached to the handle wafer;
removing the portion of the SiGe layer to expose the first silicon layer;
epitaxially growing silicon on the first silicon layer by applying trisilane at a temperature below 650 degrees Celsius to form a low temperature silicon layer on the first silicon layer; and
forming a transistor over and in the low temperature silicon layer.
14. The method of claim 13, wherein:
the step of providing the donor wafer provides the SiGe buffer layer at a germanium concentration not less than 30 percent and the silicon layer at a relaxed strain;
the step of epitaxially growing the first silicon layer grows the first silicon layer to achieve a biaxial tensile strain; and
the step of epitaxially growing silicon comprises growing the low temperature silicon with a biaxial tensile strain.
15. The method of claim 13, wherein:
the step of epitaxially growing the first silicon layer grows the first silicon layer to thickness of less than 200 Angstroms; and
the step of epitaxially growing silicon comprises growing the low temperature silicon to a thickness of greater than 500 Angstroms at a temperature of not greater than 500 degrees Celsius.
16. The method of claim 17, wherein
the step of forming the first dielectric comprises reacting dichlorosilane and nitrous oxide at a temperature of at least 750 degrees Celsius.
17. The method of claim 13, wherein the forming the first dielectric layer comprises forming the first dielectric layer of high temperature oxide formed from dichorosilane and nitrous oxide at a temperature between about 800 and 850 degrees Celsius.
18. A method of forming a semiconductor structure, comprising:
providing a donor wafer comprising a silicon germanium (SiGe) buffer layer having relaxed strain;
epitaxially growing a first silicon layer on the SiGe buffer layer;
forming a first dielectric layer on the first silicon layer by applying disilane and nitrous oxide at a temperature of at least 750 degrees Celsius;
providing a handle wafer comprising:
a supporting substrate; and
an oxide layer on the supporting substrate;

bonding the first dielectric layer to the oxide layer;
cleaving the SiGe buffer layer to leave the first dielectric layer, the first silicon layer, and a portion of the SiGe buffer layer attached to the handle wafer;
removing the portion of the SiGe buffer layer to expose the first silicon layer;
epitaxially growing silicon on the first silicon layer to form a second silicon layer on the first silicon layer; and
forming a transistor in and over the second silicon layer.
19. The method of claim 18, wherein the forming the first dielectric layer occurs at a temperature between about 800 and 850 degrees Celsius.
20. The method of claim 18, wherein:
the step of providing the donor wafer provides the SiGe buffer layer at a germanium concentration not less than 30 percent;
the step of epitaxially growing the first silicon layer grows the first silicon layer to a thickness of less than 200 Angstroms with a biaxial tensile strain; and
the step of epitaxially growing silicon comprises growing the second silicon layer to a thickness of greater than 500 Angstroms at a temperature of not greater than 500 degrees Celsius with a biaxial tensile strain.

The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.

1. A computer-implemented process of managing status changes to a work order for management reporting, and auditing activities of work order performance in a telephone facility network, the process comprising:
configuring, in a computer memory, a table of local user defined event handling rules including status change event rules wherein each status change event rule indicates one or more actions to be performed on a work order for at least one status transition resulting from a change-in-status in the performance of a work order;
acquiring, from a communications network, a telephone line record from at least one of i) results from a mechanized loop test, ii) results from an automated local loop test system, iii) information from a digital subscriber line communication system, iv) information from a fiber optic communication system, and v) information from an Integrated Services Digital Network communication system, the telephone line record comprising at least one of i) customer information from a Customer Record Information System, ii) facility information from a Loop Facility Assignment Control System, and iii) equipment information from a switch system; creating a work order using information from the acquired telephone line record and assigning the work order an initial status;
receiving, from a communications network, work order change-in-status information wherein said change-in-status information includes a work order identifier, a status code, and a generating identifier; annotating the change-in-status information with a date and a time reflecting the local time zone of a telephone system wire center where the work order is locally managed;
validating that the annotated date and the time are chronologically after a previous change in status to the work order; updating the work order with the change in status; and archiving each change in status to the work order as the work order progresses from creation to closure;
filtering the table of event handling rules for the work order change-in-status information for an event criteria, the event criteria specifying a status transition matching one or more event handling rules, wherein the work order is automatically updated according to the corresponding actions of the one or more event handling rules, wherein at least one of the one or more event handling rules includes a corresponding action to set the status of the work order to a specified status code based on the change-in-status information and corresponding action of the event handling rules; and
providing a notification, via a communications network, of the transition to the specified status based on the change-in-status information;
wherein each transition in status in the life of the work order is tracked and logged for management, reporting, and auditing activities.
2. A process of managing status changes to a work order according to claim 1, where the generating identifier is a user identifier representing a user generating the change in status of the work order.
3. A process of managing status changes to a work order according to claim 1, where the generating identifier is a system name representing a system generating the change in status of the work order.
4. A process of managing status changes to a work order according to claim 1, where the generating identifier is a software component name representing a computer software component generating the change in status of the work order.
5. A process of managing status changes to a work order according to claim 1, further comprising manually editing the date and the time to permit a user to backdate the change in status.
6. A process of managing status changes to a work order according to claim 5, further comprising retaining the annotated date and time for a comparison to the manually-edited date and time.
7. A process of managing status changes to a work order according to claim 1, further comprising identifying the work order using a telephone number.
8. A process of managing status changes to a work order according to claim 1, further comprising identifying the change in status information using a telephone number.
9. A process of managing status changes to a work order according to claim 1, further comprising communicating a notification, via the communications network, when the change in status updates the work order to an intermediate status code.
10. A system for managing status changes to a work order for management, reporting, and auditing activities of work order performance in a telephone facility network, the system comprising
a computer and a memory comprising
a Status Manager module operable to:
configure, in a computer memory, a table of local user defined event handling rules including status change event rules wherein each status change event rule indicates one or more actions to be performed on a work order for at least one status transition resulting from a change-in-status in the performance of a work order;
acquire, from a communications network, a telephone line record from at least one of i) results from a mechanized loop test, ii) results from an automated local loop test system, iii) information from a digital subscriber line communication system, iv) information from a fiber optic communication system, and v) information from an Integrated Services Digital Network communication system, the telephone line record comprising at least one of i) customer information from a Customer Record Information System, ii) facility information from a Loop Facility Assignment Control System, and iii) equipment information from a switch system; create the work order using information from the acquired telephone line record and assign the work order an initial status;

receive, from a communications network, work order change-in-status information wherein said change-in-status information includes a work order identifier, a status code, and a generating identifier;
annotate the change-in-status information with a date and a time reflecting the local time zone of a telephone system wire center where the work order is locally managed;
validate that the annotated date and the time are chronologically after a previous change in status to the work order; update the work order with the change in status; and archive each change in status to the work order as the work order progresses from creation to closure;
filter the table of event handling rules for the work order the change-in-status for an event criteria, the event criteria specifying a status transition matching one or more event handling rules, wherein the work order is automatically updated according to the corresponding actions of the one or more event handling rules, wherein at least one of the one or more event handling rules includes a corresponding action to set the status of the work order to a specified status code based on the change-in-status information and corresponding action of the event handling rules; and
provide a notification, via a communications network, of the transition to the specified status based on the change-in-status information;
wherein each change in status in the life of the work order is tracked and logged for management, reporting, and auditing activities.
11. A computer program product for managing status changes to a work order for management, reporting, and auditing activities of work order performance in a telephone facility network, the computer program product comprising:
a computer-readable medium; and
a Status Manager module stored on the computer-readable medium, the Status Manager module operable to:
configure, in a computer memory, a table of local user defined event handling rules including status change event rules wherein each status change event rule indicates one or more actions to be performed on a work order for at least one status transition resulting from a change-in-status in the performance of a work order;
acquire, from a communications network, a telephone line record from at least one of i) results from a mechanized loop test, ii) results from an automated local loop test system, iii) information from a digital subscriber line communication system, iv) information from a fiber optic communication system, and v) information from an Integrated Services Digital Network communication system, the telephone line record comprising at least one of i) customer information from a Customer Record Information System, ii) facility information from a Loop Facility Assignment Control System, and iii) equipment information from a switch system; create the work order using information from the acquired telephone line record and assign the work order an initial status;
receive, from a communications network, work order change-in-status information wherein said change-in-status information includes a work order identifier, a status code, and a generating identifier;
annotate the change-in-status information with a date and a time, reflecting the local time zone of a telephone system wire center where the work order is locally managed;
validate that the annotated date and the time are chronologically after a previous change in status to the work order; update the work order with the change in status; and archive each change in status to the work order as the work order progresses from creation to closure;
filter the table of event handling rules for the work order the change-in-status for an event criteria, the event criteria specifying a status transition matching one or more event handling rule, wherein the work order is automatically updated according to the corresponding actions of the one or more event handling rules, wherein at least one of the one or more event handling rules includes a corresponding action to set the status of the work order to a specified status code based on the change-in-status information and corresponding action of the event handling rules; and
provide a notification, via a communications network, of the transition to the specified status based on the change-in-status information;
wherein each change in status in the life of the work order is tracked and logged for management, reporting, and auditing activities.

1. A method of tracking at least one mobile unit utilizing a radio and light based 3-D positioning system; said radio and light based 3-D positioning system comprising a stationary self-positioning radio (pseudolite) transceiver, a stationary laser transmitter positioned in a location with known coordinates, at least one mobile integrated radio (pseudolite) transceiverlaser detector (RP_T&L_D), a wireless link, and a display block; said method comprising:
(A) determining position coordinates of said stationary self-positioning radio (pseudolite) transceiver based on a first plurality of external radio signals by using said stationary self-positioning radio (pseudolite) transceiver;
(B) broadcasting at least one internal radio signal by using said self-positioning radio (pseudolite) transceiver by using said wireless link; wherein said at least one internal radio signal includes position coordinates of said self-positioning radio (pseudolite) transceiver;
(C) generating at least one laser beam by using said stationary laser transmitter;
(D) broadcasting said at least one laser beam generated by said stationary laser transmitter;
(E) receiving a second plurality of external radio signals, receiving at least one said internal radio signal via said wireless link, and detecting said at least one laser beam by using said integrated radio (pseudolite) transceiverlaser detector (RP_T&L_D);
(F) determining 3-D position coordinates of said at least one mobile unit comprising said integrated radio (pseudolite) transceiverlaser detector (RP_T&L_D) based on a set of data selected from the group consisting of: said second plurality of received external radio signals; said at least one received internal radio signal; and said at least one detected laser beam;
and
(G) broadcasting said 3-D position coordinates of said at least one mobile unit by using said integrated radio (pseudolite) transceiverlaser detector (RP_T&L_D) via said wireless link.
2. The method of claim 1, wherein said step (A) further comprises:
(A1) receiving said first plurality of external radio signals broadcasted by at least one radio source selected from the group consisting of: GPS; GLONASS; combined GPSGLONASS; GALILEO; Global Navigational Satellite System (GNSS); and a pseudolite transmitter by said stationary self-positioning radio (pseudolite) transceiver.
3. The method of claim 1, wherein said step (C) further comprises:
(C1) generating a reference laser beam providing a high accuracy vertical coordinate by using a plane laser transmitter.
4. The method of claim 1, wherein said step (C) further comprises:
(C2) generating at least one rotating fan-shaped laser beam by using a fan laser transmitter.
5. The method of claim 1, wherein said step (E) further comprises:
(E1) receiving said second plurality of external radio signals broadcasted by at least one radio source selected from the group consisting of: GPS; GLONASS; combined GPSGLONASS; GALILEO; Global Navigational Satellite System (GNSS); and a pseudolite transmitter by said at least one mobile unit comprising said integrated radio (pseudolite) transceiverlaser detector (RP_T&L_D).
6. The method of claim 1, wherein said step (F) further comprises:
(F1) determining 3-D position coordinates of said mobile unit comprising said integrated radio (pseudolite) transceiverlaser detector (RP_T&L_D) at the first level of accuracy based on said second plurality of received external radio signals;
and
(F2) determining an elevation coordinate of said mobile unit comprising said integrated radio (pseudolite) transceiverlaser detector (RP_T&L_D) at the second level of accuracy based on said at least one detected laser beam; wherein a set of measurements determined at said second level of accuracy is more accurate than said set of measurements determined at said first level of accuracy.
7. The method of claim 1, wherein said step (F) further comprises:
(F3) determining 3-D position coordinates of said mobile unit comprising said integrated radio (pseudolite) transceiverlaser detector (RP_T&L_D) at the first level of accuracy based on said second plurality of received external radio signals and based on said at least one received internal radio signal;
and
(F4) determining an elevation coordinate of said mobile unit comprising said integrated radio (pseudolite) transceiverlaser detector (RP_T&L_D) at the second level of accuracy based on said at least one detected laser beam; wherein a set of measurements determined at said second level of accuracy is more accurate than said set of measurements determined at said first level of accuracy.
8. The method of claim 1, wherein said step (F) further comprises:
(F5) assigning different weights to different sets of measurement data based on a measurement algorithm by using a weighting processor; wherein said measurement algorithm is optimized to take into account at least one measurement site parameter at the time of measurement; and wherein each said measurement site parameter is selected from the group consisting of: topology of said site; weather conditions at said site; and visibility of at least one said laser beam at said site.
9. The method of claim 1, wherein said integrated radio (pseudolite) Transceiverlaser detector (RP_T&L_D) further comprises a first radio (pseudolite) transceiver and a second radio (pseudolite) transceiver, wherein said step (G) further comprises:
(G1) broadcasting said 3-D position coordinates of said mobile unit by using said first radio (pseudolite) transceiver via said wireless link.
10. The method of claim 1, wherein said integrated radio (pseudolite) transceiverlaser detector (RP_T&L_D) further comprises a first radio (pseudolite) transceiver and a second radio (pseudolite) transceiver, wherein said step (G) further comprises:
(G2) broadcasting said 3-D position coordinates of said mobile unit by using said second radio (pseudolite) transceiver via said wireless link.
11. The method of claim 1 further comprising:
(H) receiving said 3-D position coordinates of said at least one mobile unit by said self-positioning radio (pseudolite) transceiver.
12. The method of claim 11, wherein said stationary self-positioning radio (pseudolite) transceiver further comprises a display block, said step (H) further comprising:
(H1) displaying location of said at least one mobile unit on said display block.
13. A method of tracking at least one mobile unit utilizing a radio and light based 3-D positioning system; said radio and light based 3-D positioning system comprising a stationary self-positioning radio (pseudolite) transceiver, a stationary laser transmitter positioned in a location with known coordinates, at least one mobile integrated radio (pseudolite) transceiverlaser detector (RP_T&L_D), a wireless link, and a display block; said method comprising:
(A) determining position coordinates of said stationary self-positioning radio (pseudolite) transceiver based on a first plurality of external radio signals by using said stationary self-positioning radio (pseudolite) transceiver;
(B) broadcasting at least one internal radio signal by using said self-positioning radio (pseudolite) transceiver via said wireless link;
(C) generating at least one laser beam by using said stationary laser transmitter;
(D) broadcasting said at least one laser beam generated by said stationary laser transmitter;
and
(E) receiving 3-D position coordinates of said at least one mobile unit broadcasted by said integrated radio (pseudolite) transceiverlaser detector (RP_T&L_D) by said stationary self-positioning radio (pseudolite) transceiver via said wireless link.
14. The method of claim 13 further comprising:
(F) displaying location of said at least one mobile unit on said display block.
15. A method of reporting by at least one mobile unit utilizing a radio and light based 3-D positioning system; said radio and light based 3-D positioning system comprising a stationary self-positioning radio (pseudolite) transceiver, a stationary laser transmitter positioned in a location with known coordinates, at least one mobile integrated radio (pseudolite) transceiverlaser detector (RP_T&L_D), and a wireless link; said method comprising:
(A) receiving a second plurality of external radio signals, receiving at least one internal radio signal broadcasted by said stationary self-positioning radio (pseudolite) transceiver via said wireless link, and detecting said at least one laser beam generated by said stationary laser transmitter positioned in said location with known coordinates by using said integrated radio (pseudolite) transceiverlaser detector (RP_T&L_D);
(B) determining 3-D position coordinates of said at least one mobile unit comprising said integrated radio (pseudolite) transceiverlaser detector (RP_T&L_D) based on a set of data selected from the group consisting of: said second plurality of received external radio signals; said at least one received internal radio signal; and said at least one detected laser beam;
and
(C) broadcasting said 3-D position coordinates of said at least one mobile unit comprising said integrated radio (pseudolite) transceiverlaser detector (RP_T&L_D) via said wireless link.

The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.

What is claimed is:

1. A semiconductor device comprising:
a first semiconductor layer of a first conductivity type;
a second semiconductor layer of a second conductivity type provided on the first semiconductor layer;
a trench penetrating the second semiconductor layer and intruding into the first semiconductor layer;
a thick gate insulating film provided on a inner wall of the trench below an upper surface of the first semiconductor layer;
a thin gate insulating film provided on the inner wall of the trench at a part upper than the thick gate insulating film;
a gate electrode filling the trench; and
a semiconductor region of a second conductivity type selectively formed to adjoin the trench and to project from a bottom surface of the second semiconductor layer into the first semiconductor layer.
2. The semiconductor device according to claim 1, wherein:
a lower end of a part of the semiconductor region of the second conductivity type in contact with the trench is substantially at a same level as a boundary between the thick gate insulating film and the thin gate insulating film.
3. The semiconductor device according to claim 1, wherein:
a carrier concentration of the semiconductor region of the second conductivity type is higher than a carrier concentration of the first semiconductor layer and lower than a carrier concentration of the second semiconductor layer.
4. The semiconductor device according to claim 1, wherein:
the thick gate insulating film has a thickness smaller than a half of a width of the trench,
a recess enclosed by the thick gate insulating film is provided near a bottom of the trench, and
the gate electrode fills the recess.
5. The semiconductor device according to claim 1, wherein:
a bottom of the trench is filled with the thick gate insulating film so that a flat surface is formed by the thick gate insulating film.
6. The semiconductor device according to claim 1, wherein:
the semiconductor region of the second conductivity type is formed in a self-aligning fashion to the thick gate insulating film.
7. The semiconductor device according to claim 1, wherein:
a channel is able to be formed near the trench in a part of the second semiconductor layer and in a part of the semiconductor region by applying a predetermined voltage to the gate electrode.
8. A semiconductor device comprising:
a first semiconductor layer of a first conductivity type;
a second semiconductor layer of a second conductivity type provided on the first semiconductor layer;
a trench penetrating the second semiconductor layer and intruding into the first semiconductor layer;
a thick gate insulating film provided on a inner wall of the trench below an upper surface of the first semiconductor layer;
a thin gate insulating film provided on the inner wall of the trench at a part upper than the thick gate insulating film;
a gate electrode filling the trench; and
a semiconductor region of a second conductivity type adjoining the trench, the semiconductor region being formed by selectively reversing the conductivity type of a part of the first semiconductor layer near the second semiconductor layer.
9. The semiconductor device according to claim 8, wherein:
a lower end of a part of the semiconductor region of the second conductivity type in contact with the trench is substantially at a same level as a boundary between the thick gate insulating film and the thin gate insulating film.
10. The semiconductor device according to claim 8, wherein:
a carrier concentration of the semiconductor region of the second conductivity type is higher than a carrier concentration of the first semiconductor layer and lower than a carrier concentration of the second semiconductor layer.
11. The semiconductor device according to claim 8, wherein:
the thick gate insulating film has a thickness smaller than a half of a width of the trench,
a recess enclosed by the thick gate insulating film is provided near a bottom of the trench, and
the gate electrode fills the recess.
12. The semiconductor device according to claim 8, wherein:
a bottom of the trench is filled with the thick gate insulating film so that a flat surface is formed by the thick gate insulating film.
13. The semiconductor device according to claim 8, wherein:
the semiconductor region of the second conductivity type is formed in a self-aligning fashion to the thick gate insulating film.
14. The semiconductor device according to claim 8, wherein:
a channel is able to be formed near the trench in a part of the second semiconductor layer and in a part of the semiconductor region by applying a predetermined voltage to the gate electrode.
15. A method to manufacture a semiconductor device comprising:
forming a first semiconductor layer of a first conductivity type, a second semiconductor layer of a second conductivity type provided on the first semiconductor layer, a trench penetrating the second semiconductor layer and intruding into the first semiconductor layer, and a thick gate insulating film provided on a inner wall of the trench below an upper surface of the first semiconductor layer;
introducing an impurity of a second conductivity type into a part of the first semiconductor layer above the thick gate insulating film and adjoining the trench to form a semiconductor region of a second conductivity type;
forming a thin gate insulating film on the inner wall of the trench at a part upper than the thick gate insulating film; and
filling the trench with a gate electrode.
16. The method to manufacture a semiconductor device according to claim 15 wherein:
the semiconductor region of the second conductivity type is formed by introducing the impurity of the second conductivity type from an inner wall of the trench by using the thick gate insulating film as a mask.
17. The method to manufacture a semiconductor device according to claim 15 wherein:
the semiconductor region of the second conductivity type is formed by implanting the impurity of the second conductivity type from a surface of the second semiconductor layer.
18. The method to manufacture a semiconductor device according to claim 15 wherein:
the forming the thin gate insulating film is performed before the introducing the impurity of the second conductivity type, and
the impurity of the second conductivity type is introduced through the thin gate insulating film into the part of the first semiconductor layer.
19. The method to manufacture a semiconductor device according to claim 15 wherein:
a lower end of a part of the semiconductor region of the second conductivity type in contact with the trench is substantially at a same level as a boundary between the thick gate insulating film and the thin gate insulating film.
20. The method to manufacture a semiconductor device according to claim 15 wherein:
a carrier concentration of the semiconductor region of the second conductivity type is higher than a carrier concentration of the first semiconductor layer and lower than a carrier concentration of the second semiconductor layer.