1. A semiconductor device, comprising:
a semiconductor substrate having a first conductivity type and a top substrate surface;
a buried layer below the top substrate surface, wherein the buried layer has a second conductivity type that is different from the first conductivity type;
a sinker region between the top substrate surface and the buried layer, wherein the sinker region has the second conductivity type, and an isolation structure is formed by the sinker region and the buried layer;
an active device in a portion of the semiconductor substrate contained by the isolation structure, wherein the active device includes a source region of the first conductivity type; and
a diode circuit connected between the isolation structure and the source region.
2. The semiconductor device of claim 1, wherein the diode circuit comprises:
a Schottky diode formed from a Schottky contact coupled with the isolation region.
3. The semiconductor device of claim 2, wherein the diode circuit further comprises:
a resistive network in series with the Schottky diode.
4. The semiconductor device of claim 2, wherein the diode circuit further comprises:
a resistive network in parallel with the Schottky diode.
5. The semiconductor device of claim 2, wherein the diode circuit further comprises:
a resistive network in series with the Schottky diode; and
a resistive network in parallel with the Schottky diode.
6. The semiconductor device of claim 2, further comprising:
a further region of the first conductivity type extending into the sinker region and partially across the sinker region, wherein the diode circuit comprises the Schottky diode and a PN junction diode formed between the further region and the sinker region.
7. The semiconductor device of claim 2, further comprising:
a first further region of the first conductivity type extending into the sinker region and partially across the sinker region at an interior wall of the sinker region; and
a second further region of the first conductivity type extending into the sinker region and partially across the sinker region at an exterior wall off the sinker region, wherein a portion of the sinker region is present at the top substrate surface between the first further region and the second further region, and wherein the diode circuit comprises the Schottky diode, a first PN junction diode formed between the first further region and the sinker region, and a second PN junction diode formed between the second further region and the sinker region.
8. The semiconductor device of claim 2, wherein the sinker region is formed as a ring that substantially surrounds the active area, the Schottky contact is positioned at a first portion of the ring, and the device further comprises:
one or more additional Schottky contacts positioned portions of the ring that are spatially separated from the first portion and from each other; and
a plurality of further regions of the first conductivity type extending from the top substrate surface into the sinker region at a top surface of the sinker region, wherein the plurality of further regions are positioned at other portions of the ring that are interspersed between the Schottky contacts.
9. The semiconductor device of claim 1, further comprising:
a further region of the first conductivity type extending into the sinker region, wherein the diode circuit comprises a PN junction diode formed between the further region and the sinker region.
10. The semiconductor device of claim 1, wherein the diode circuit comprises a polycrystalline silicon diode interconnected between the source region and the sinker region.
11. The semiconductor device of claim 1, wherein the active device comprises:
a drift region of the first conductivity type within a central portion of the active area and extending from the top substrate surface into the semiconductor substrate;
a drain region of the first conductivity type extending into the drift region from the top substrate surface;
a body region of the second conductivity type extending from the top substrate surface into the semiconductor substrate between the drift region and the isolation structure; and
a source region of the first conductivity type extending into the body region from the top substrate surface.
12. A driver circuit comprising:
a first laterally diffused metal oxide semiconductor field effect transistor (LDMOSFET) formed on a semiconductor substrate having a first conductivity type and a top substrate surface, wherein the first LDMOSFET includes
a buried layer below the top substrate surface, wherein the buried layer has a second conductivity type that is different from the first conductivity type,
a sinker region between the top substrate surface and the buried layer, wherein the sinker region has the second conductivity type, and an isolation structure is formed by the sinker region and the buried layer,
an active device in a portion of the semiconductor substrate contained by the isolation structure, wherein the active device includes a source region of the first conductivity type, and
a diode circuit connected between the isolation structure and the source region.
13. The driver circuit of claim 12, wherein the diode circuit comprises:
a Schottky diode formed from a Schottky contact coupled with the isolation region.
14. The driver circuit of claim 12, further comprising:
a further region of the first conductivity type extending into the sinker region, wherein the diode circuit comprises a PN junction diode formed between the further region and the sinker region.
15. The driver circuit of claim 12, wherein the diode circuit comprises a polycrystalline silicon diode interconnected between the source region and the sinker region.
16. The driver circuit of claim 12, wherein the diode circuit comprises:
a diode; and
a resistive network in series with the diode.
17. The driver circuit of claim 12, wherein the diode circuit comprises:
a diode; and
a resistive network in parallel with the diode.
18. The driver circuit of claim 12, wherein the diode circuit comprises:
a diode;
a resistive network in series with the diode; and
a resistive network in parallel with the diode.
19. A method for forming a semiconductor device, the method comprising the steps of:
forming a buried layer below a top substrate surface of a semiconductor substrate having a first conductivity type, wherein the buried layer has a second conductivity type that is different from the first conductivity type;
forming a sinker region between the top substrate surface and the buried layer, wherein the sinker region has the second conductivity type, and an isolation structure is formed by the sinker region and the buried layer;
forming an active device in a portion of the semiconductor substrate contained by the isolation structure, wherein the active device includes a source region of the first conductivity type; and
forming a diode circuit connected between the isolation structure and the source region.
20. The method of claim 19, wherein forming the diode circuit comprises:
forming a Schottky contact coupled with the isolation region.
21. The method of claim 19, wherein forming the diode circuit comprises:
forming a further region of the first conductivity type extending into the sinker region, wherein the diode circuit comprises a PN junction diode formed between the further region and the sinker region.
22. The method of claim 19, wherein forming the diode circuit comprises:
forming and interconnecting a polycrystalline silicon diode between the drain region and the sinker region.
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. An optic comprising:
a wedge-shaped light guide having opposing first and second faces; and
a turning film bonded to the wedge-shaped light guide via an interface layer, the turning film comprising a plurality of facets oblique to the first face of the wedge-shaped light guide and supporting a dichroic coating.
2. The optic of claim 1, wherein the plurality of facets are parallel to each other and disposed between 15 and 45 degrees with respect to the first face of the wedge-shaped light guide.
3. The optic of claim 1, wherein the dichroic coating is at least partially transparent in a visible wavelength band and reflective in an infrared wavelength band.
4. The optic of claim 3, wherein the visible wavelength band comprises at least some light less than 700 nanometers in wavelength.
5. The optic of claim 3, wherein the infrared wavelength band comprises at least some light greater than 800 nanometers in wavelength.
6. The optic of claim 1, wherein the wedge-shaped light guide comprises a material having a first refractive index, wherein the first face supports a cladding layer having a second refractive index less than the first refractive index, and wherein the interface layer has a third refractive index substantially equal to the first refractive index.
7. The optic of claim 6, wherein the cladding layer is a first cladding layer, and wherein the second face supports a second cladding layer having a fourth refractive index less than the first refractive index and nearer to the second refractive index than to the first refractive index.
8. The optic of claim 6, wherein the cladding layer comprises a fluoropolymer.
9. The optic of claim 1, wherein the interface layer comprises an adhesive.
10. The optic of claim 9, wherein the adhesive comprises a polyacrylic adhesive.
11. The optic of claim 9, wherein the adhesive comprises an ultraviolet-curable adhesive.
12. A system comprising a touch-sensitive display configured to detect touch by capturing an image of one or more objects disposed on a touch-sensitive display surface, the system comprising:
an infrared illuminant configured to illuminate the one or more objects from behind the touch-sensitive display surface with light having a median wavelength;
a detector configured to capture the image; and
an optic configured to deliver to the detector light reflected from the one or more objects, the optic comprising:
a wedge-shaped light guide having opposing first and second faces; and
a turning film bonded to the wedge-shaped light guide, the turning film comprising a plurality of facets oblique to the first face of the wedge-shaped light guide and supporting a dichroic coating.
13. The system of claim 12, wherein the infrared illuminant comprises an infrared light-emitting diode.
14. The system of claim 12, wherein the detector comprises an infrared-sensitive camera.
15. A system comprising a touch-sensitive display configured to detect touch by capturing an image of one or more objects disposed on a touch-sensitive display surface while displaying a visible image on the touch-sensitive display surface, the system comprising:
an infrared illuminant configured to illuminate the one or more objects from behind the touch-sensitive display surface with light having a median wavelength;
a detector configured to capture the image;
an optic configured to focus on the detector light reflected from the one or more objects and to attenuate a reflection of the light, the optic comprising:
a wedge-shaped light guide having opposing first and second faces and comprising a material having a first refractive index, the first face supporting a cladding layer having a second refractive index less than the first refractive index, a thickness of the cladding layer an odd-integer multiple of one-half of the median wavelength; and
a turning film bonded to the cladding layer via an interface layer, the interface layer having a third refractive index matched to the first refractive index, the turning film comprising a plurality of facets oblique to the first face of the wedge-shaped light guide and supporting a dichroic coating;
an image-creating subsystem adapted to create the visible image, and comprising a visible illuminant configured to project visible light through the optic in a direction toward the touch-sensitive display surface and substantially normal to the opposing first and second faces.
16. The system of claim 15, wherein the first illuminant comprises an infrared light-emitting diode.
17. The system of claim 15, wherein the detector comprises an infrared-sensitive camera.
18. The system of claim 15, wherein the image-creating subsystem further comprises an image-forming light valve disposed between the optic and the touch-sensitive display surface.
19. The system of claim 18, wherein the image-forming light valve comprises a liquid-crystal display device.