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.