Claims
- 1. A method for essentially permanently storing binary data in an archival memory semiconductor target, comprising the steps of:
- (a) providing a substrate of a semiconductor material having a first polarity type, said substrate having a surface;
- (b) fabricating a layer of the remaining polarity type of the semiconductor material upon and substantially completely across the surface of said substrate;
- (c) assigning a two-dimensional array of potential data storage sites upon a surface of the fabricated layer furthest from said substrate surface;
- (d) damaging the lattice of the semiconductor layer over a portion of each data storage site at which a first value of binary information is to be stored; and
- (e) maintaining the lattice of the semiconductor layer at the remaining data storage sites in undamaged condition to store a remaining value a binary information.
- 2. A method as set forth in claim 1, further comprising the step of:
- (f) interrogating sequential ones of a multiplicity of data storage sites to read the value of binary information stored at each of said multiplicity of sites.
- 3. A method as set forth in claim 2, wherein step (f) comprises the steps of: directing a beam of electrons into the fabricated layer at each of said multiplicity of data sites to generate electron-hole pairs therein; reverse biasing the junction between said substrate and said fabricated layer to create a depletion region thereabout; and monitoring the current caused to flow to said depletion region through said substrate to read the value of binary information stored at the data site upon which the electron beam impinges.
- 4. A method as set forth in claim 2, further comprising the step of accelerating the electrons to an average energy in the vicinity of about 2 KeV.
- 5. The method as set forth in claim 1, wherein step (d) comprises the steps of: providing a source of ions; accelerating the ions into a finely collimated beam; scanning the beam of ions sequentially to the surface of said layer at each of the data sites defined on said target; and modulating said beam to impinge only upon said layer surface at each data site at which the first value of binary information is to be stored by inducing damage to the lattice of said fabricated layer thereat.
- 6. A method as set forth in claim 5, wherein said ions are of a material selected from the group consisting of helium, argon, krypton, xenon, neon, boron, nitrogen and arsenic.
- 7. A method as set forth in claim 5, wherein the ions are of one of the noble gas elements.
- 8. A method as set forth in claim 5, wherein the ions are ionized molecules.
- 9. A method as set forth in claim 5, further comprising a step of establishing the fluence of the beam of ions to be on the order of 10.sup.10 to 10.sup.13 ions per square centimeter.
- 10. A method as set forth in claim 9, further comprising the step of accelerating the electrons to an energy in the region of 30-100 KeV.
- 11. A method as set forth in claim 5, further comprising the step of:
- (f) interrogating sequential ones of a multiplicity of data storage sites to read the value of binary information stored at each of said multiplicity of sites.
- 12. A method as set forth in claim 11, wherein step (f) comprises the steps of:
- directing a beam of electrons from the same direction as the beam of ions and into the fabricated layer at each of said multiplicity of data sites to generate electron hole pairs therein; reverse biasing the junction between said substrate and said fabricated layer to create a depletion region thereabout; and monitoring the current caused to flow to said depletion region through said substrate to read the value of binary information stored at the data site upon which the electron beam impinges.
Government Interests
The invention herein described was made in the course of or under a contract or subcontract thereunder, with the Department of the Air Force.
US Referenced Citations (3)