Claims
- 1. A method of fabricating a capacitor coupled contactless imager structure in a semiconductor substrate of p-type conductivity while simultaneously fabricating a metal-oxide-semiconductor (MOS) transistor structure in said semiconductor substrate, the method comprising:
- (a) forming first and second spaced-apart wells of n-type conductivity (n-wells) in the semiconductor substrate, the first and second n-wells having a region of isolation oxide formed therebetween, the first n-well forming the collector region of the imager structure;
- (b) forming a first mask that covers the second n-well;
- (c) forming a p-type region in the first n-well, the p-type region forming the base region of the imager structure;
- (d) after removing the first mask from the second n-well, forming a layer of gate oxide on the first n-well and on the second n-well;
- (e) forming a second mask that covers the second n-well and that covers a peripheral portion of the first n-well while leaving gate oxide formed on a central portion of the first n-well exposed;
- (f) removing the exposed gate oxide from the central portion of the first n-well;
- (g) after removing the second mask, forming a first polysilicon layer over a structure resulting from foregoing steps (a)-(g) and patterning the first polysilicon layer to form a polysilicon emitter contact region on the central portion of the first n-well and a polysilicon gate electrode on the gate oxide on the second n-well;
- (h) forming a silicon dioxide layer over the polysilicon emitter contact region and exposed surfaces of the first n-well and over the polysilicon gate electrode and exposed surfaces of the second n-well;
- (i) forming a second polysilicon layer over the structure resulting from foregoing steps (a)-(h) and patterning the second polysilicon layer to provide a polysilicon upper capacitor plate on the silicon dioxide layer over the first n-well, the polysilicon upper capacitor plate covering the entire base region of the imager structure.
- 2. A method as in claim 1, and wherein the polysilicon upper capacitor plate is about 500.degree.-600.degree. thick.
Parent Case Info
This is a divisional of application Ser. No. 08/438,347, filed May 10, 1995 of Albert Bergemont, et al. for METHOD OF MANUFACTURING A THIN POLY, CAPACITOR COUPLED CONTACTLESS IMAGER WITH HIGH RESOLUTION AND WIDE DYNAMIC RANGE, now abandoned.
US Referenced Citations (6)
Foreign Referenced Citations (2)
Number |
Date |
Country |
0 562 523 A1 |
Sep 1993 |
EPX |
364015967 A |
Jan 1989 |
JPX |
Non-Patent Literature Citations (1)
Entry |
Eric R. Fossum, "Active-pixel sensors challenge CCDs", Laser Focus World, Technology Guide: Detector Handbook, Jun. 1993, pp. 83-87. |
Divisions (1)
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Number |
Date |
Country |
Parent |
438347 |
May 1995 |
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