Solid-state light-sensitive storage device

Claim 2

A storing device in an information system as set forth in claim 1 wherein said high-resistivity semiconductor substrate is P-type silicon having a resistivity of at least 1,000 ohms-cm.

Claim 3

A storing device in an information system as set forth in claim 3 wherein said PN-junction is formed by diffusing an N-type impurity into the P-type substrate.

Claim 4

A storing device in an information system wherein data is stored in the form of a charge pattern that varies in accordance with the quantity of illumination incident on the storing device comprising: an N-type high-resistivity semiconductor substrate, and an epitaxial layer of P-type semicoNductor material extending over the active region of one surface of said substrate and producing a single PN-junction therewith, a depletion region being formed adjacent said PN-junction that is caused to grow by a scanning electron beam to extend throughout the thickness of said epitaxial layer, said depletion region minimizing lateral diffusion of charge carriers thereby effecting a storage device having extremely high resolution.

Claim 5

A storing device in an information system as set forth in claim 5 including a guard ring surrounding the PN-junction to isolate the active area of said target.

Claim 6

A light sensitive storage system comprising in combination: a semiconductor target comprising a high-resistivity P-type substrate having an active region on one surface thereof, an N-type region being formed in said active region to produce a single PN-junction, said PN-junction producing a depletion region in said substrate adjacent said junction; means for scanning an electron beam across the exposed surface of said P-type substrate to extend said depletion region throughout the thickness of said substrate thereby charging said PN-junction to a reference potential, the surface of said P-type material facing said electron beam becoming substantially charged with electrons; means for directing light upon said N-type material to produce hole-electron pairs which diffuse to said PN-junction said holes being swept across said PN-junction to combine with electrons at said electron-charged surface thereby reducing said reference potential across said PN-junction by an amount proportional to the intensity of said light; and means for measuring the change in said reference potential stored by said target to produce a signal representing the intensity of light impinging on said target.

Claim 7

A light sensitive storage system as set forth in claim 7 wherein a guard ring is formed to surround said PN-junction to isolate the active area of said semiconductor target.

Claim 8

A light sensitive storage system as set forth in claim 7 further including a layer of high-resistivity material formed to overlie the exposed surface of said P-type material.

Claim 9

A light sensitive storage system comprising in combination: a semiconductor target comprising a high-resistivity N-type substrate having an active region on one surface thereof, a P-type region being formed in said active region to produce a single PN-junction, said PN-junction producing a depletion region in said substrate adjacent said junction; means for scanning an electron beam across the exposed surface of said P-type region to extend said depletion region throughout the thickness of said P-type material thereby charging said PN-junction to a reference potential, the exposed surface of said P-type material becoming charged with electrons; means for directing light to impinge upon said N-type substrate to produce hole-electron pairs which diffuse to said PN-junction, said holes being swept across said PN-junction to combine with electrons at said electron-charged surface thereby reducing said reference potential across said single PN-junction by an amount proportional to the intensity of said light; and means for measuring the change in said reference potential stored by said target to produce a signal representing the intensity of light impinging on said target.

Claim 10

A light sensitive storage system as set forth in claim 10 wherein a guard ring is formed to surround said PN-junction to isolate the active area of said semiconductor target.

Claim 11

A light sensitive storage system as set forth in claim 10 further including a layer of high-resistivity material formed to overlie the exposed portion of said P-type material.