EP0133709A2
Expired / Lapsed
EP
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Photodetector integrated circuit
Assignee: ITT Inc
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Filing: 1984-08-11
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Granted: —
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Expires: 2004-08-11
Abstract
Abstract An integrated circuit incorporating a PIN diode connected to the gate of an FET, wherein the semiconductive layers used to construct the diode are also the layers used to construct the FET, and provide a relatively low capacitance per unit area for the diode compared with that ot the gate of the FET.
Inventors
- 👤 John Christopher Greenwood
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-29 22:23
CPC Classifications
H; H10; H10F; H10F99/00; H10F39/00; H10F39/10; H10F39/103; H10D; H10D84/00; H10D84/01; H10D84/02; H10D84/05; H10F30/00; H10F30/20; H10F30/21; H10F30/22; H10F30/223; H10P; H10P50/00; H10P50/60; H10P50/64; H10P50/642; H10P50/646
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
71 words
A photodetector integrated circuit incorporating a PIN photodiode (PIN-diode) connnected to the gate of field effect transistor (FET), wherein the semiconductive layers from which the diode is constructed are also the layers from which the FET is constructed, and their construction is such as to provide the PIN-diode with a capacitance per unit area that is small compared with the gate capacitance of the FET per unit area of that gate.
Claim 2
Dependent Claim
71 words
A photodetector integrated circuit incorporating a PIN photodiode (PIN-diode) connnected to the gate of field effect transistor (FET), wherein the semiconductive layers from which the diode is constructed are also the layers from which the FET is constructed, and their construction is such as to provide the PIN-diode with a capacitance per unit area that is small compared with the gate capacitance of the FET per unit area of that gate.
Claim 3
Dependent Claim
49 words
An integrated circuit as claimed in claim 1, wherein the semiconductive layers are grown upon an indium phosphide substrate and include an n-type layer that-forms the channel layer (4) of the FET and covers an n -type or semi-insulating buffer layer (3) that is thicker than the channel layer.
Claim 4
Dependent Claim
40 words
An integrated circuit as claimed in claim 2, wherein the buffer layer (3) is approximately 1 micron thick and is made of material having a band gap that is less than that of any layer with which it is covered.
Claim 5
Dependent Claim
54 words
An integrated circuit as claimed in claim 2 or 3, wherein the buffer layer (3) is approximately 1 micron thick and is made of material having a band gap that is less than that of the substrate of the integrated circuit and of any layer intermediate the buffer layer (3) and the substrate (1).
Claim 6
Dependent Claim
15 words
An integrated circuit as claimed in any preceding claim, wherein the FET is a HEMT.
Claim 7
Dependent Claim
38 words
An integrated circuit as claimed in claim 1, 2, 3 or 4, wherein the FET is of a type in which source drain current conduction occurs in the channel layer (4) rather than in the buffer layer (3).
Claim 8
Dependent Claim
15 words
An integrated circuit as claimed in any preceding claim, wherein the FET is a JFET.
Claim 9
Dependent Claim
75 words
An integrated circuit as claimed in claim 6, wherein the p-n junction is bounded on its upper side by a stack of three layers (4,5,6) whose compositions lie in the range from indium phosphide through gallium indium arsenide phosphide to gallium indium arsenide, and are such that the topmost has a band gap in the region of 1.2 eV, the bottommost a substantially higher band gap, and the middle layer a substantially lower band gap.
Claim 10
Dependent Claim
20 words
An integrated circuit as claimed in any preceding claim, which integrated circuit includes a bias resistor for the PIN diode.
Claim 11
Dependent Claim
43 words
An integrated circuit as claimed in claim 9, which integrated circuit includes a second FET whose gate is connected to the drain of the first FET and which integrated circuit also includes a load resistor connected to the drain of the first FET.
References Cited (Backward Citations)
No citation records indexed.
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