Abstract A process for producing light emitting diodes is disclosed. In the process a major planar surface of a single crystal silicon wafer is modified to acceptably match the crystallographic lattice constant of a preselected electroluminescent single crystal semiconductor, such as gallium phosphide. The preselected electroluminescent semiconductor material is then epitaxially deposited in single crystal form on the modified surface of the silicon wafer, a step which is not feasible without the modification of the silicon wafer surface. Preferably, the modification is achieved by epitaxially depositing a thin layer of semiconductor material whose lattice structure offers, a substantially smaller disparity with the structure of the electroluminescent material than the existing disparity between the silicon wafer and the electroluminescent material.
A method of fabricating a monolithic semiconductor display in a single crystal silicon substrate comprising: epitaxially depositing on a plurality of selected regions of a surface of said silicon substrate a thin layer of an alloy of silicon to form a graded layer on each selected region having a crystal lattice constant substantially matching the crystal lattice constant of said silicon substrate at the boundary therebetween and having a crystal lattice constant substantially matching the crystal lattice constant of a preselected electroluminescent single crystal semiconductor material at a second surface; thereafter epitaxially depositing a layer of said preselected electroluminescent semiconductor material on each of said thin layers; forming a planar p-n junction in each of said layers of electroluminescent semiconductor material to form a plurality of light emitting diodes for said display; and forming p-n junctions in said substrate and said graded epitaxial layer to form an active semiconductor component different from said light emitting diodes.
Claim 2
Independent Claim
156 words
A method of fabricating a monolithic semiconductor display in a single crystal silicon substrate comprising: epitaxially depositing on a plurality of selected regions of a surface of said silicon substrate a thin layer of an alloy of silicon to form a graded layer on each selected region having a crystal lattice constant substantially matching the crystal lattice constant of said silicon substrate at the boundary therebetween and having a crystal lattice constant substantially matching the crystal lattice constant of a preselected electroluminescent single crystal semiconductor material at a second surface; thereafter epitaxially depositing a layer of said preselected electroluminescent semiconductor material on each of said thin layers; forming a planar p-n junction in each of said layers of electroluminescent semiconductor material to form a plurality of light emitting diodes for said display; and forming p-n junctions in said substrate and said graded epitaxial layer to form an active semiconductor component different from said light emitting diodes.
Claim 3
Dependent Claim
23 words
The method according to claim 1, wherein said layer of electroluminescent material is selected from the group consisting of GaP, GaAs, and GaAsP.
Claim 4
Dependent Claim
16 words
The method according to claim 1 wherein said semiconductor component is formed to be a transistor.
Claim 5
Dependent Claim
25 words
The method according to claim 3 wherein said transistor is formed so as to be a part of the drive circuit for the electroluminescent layer.
Claim 6
Dependent Claim
33 words
The method of claim 1 wherein said thin layer is deposited to form a graded layer by vapor phase deposition and hydrogen reduction of a varying ratio of silicon tetrachloride and germanium tetrachloride.
Claim 7
Dependent Claim
23 words
The method of claim 1 wherein said thin layer is deposited by thermal decomposition of a varying ratio of silane and germanium tetrachloride.
Claim 8
Dependent Claim
22 words
The method of claim 1 wherein said thin layer deposited by thermal decomposition of a varying ratio of trichlorosilane and germanium tetrachloride.
Claim 9
Dependent Claim
33 words
The method of claim 1 wherein said silicon alloy is silicon and germanium in which the germanium concentration is zero at said substrate boundary and under 10 mole percent at said second surface.