A method of manufacturing silicon germanium-on-insulator
AssigneeSunEdison Semiconductor Limited
InventorsGang Wang, Shawn George Thomas
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Abstract
The disclosed method is suitable for producing a SiGe-on-insulator structure. According to some embodiments of the method, a layer comprising SiGe is deposited on silicon-on-insulator substrate comprising an ultra-thin silicon top layer. In some embodiments, the layer comprising SiGe is deposited by epitaxial deposition. In some embodiments, the SiGe epitaxial layer is high quality since it is produced by engineering the strain relaxation at the Si/buried oxide interface. In some embodiments, the method accomplishes elastic strain relaxation of SiGe grown on a few monolayer thick Si layer that is weakly bonded to the underline oxide.
Claims35
A method of preparing a multilayer structure, the method comprising:
- etching a silicon layer of a silicon-on-insulator substrate, wherein the silicon-on-insulator substrate comprises (i) a single crystal semiconductor handle layer comprising two major, generally parallel surfaces, one of which is a front surface of the single crystal semiconductor handle layer and the other of which is a back surface of the single crystal semiconductor handle layer, a circumferential edge joining the front and back surfaces of the single crystal semiconductor handle layer, a central plane between and parallel to the front surface and the back surface of the single crystal semiconductor handle layer, a central axis perpendicular to the central plane, and a bulk region between the front and back surfaces of the single crystal semiconductor handle layer, (ii) a dielectric layer in interfacial contact with the front surface of the single crystal semiconductor handle layer, and (ii) the silicon layer in interfacial contact with the dielectric layer, and further wherein the silicon layer is etched to a thickness between about 0.5 nanometer and about 4 nanometers, as measured along the central axis;
- depositing a first layer comprising germanium on the etched silicon layer;
- annealing the silicon-on-insulator substrate comprising the etched silicon layer and the first layer comprising germanium at a temperature and duration sufficient to interdiffuse germanium from the first layer into the etched silicon layer, to thereby yield a second layer comprising silicon and germanium having a formula of SixGe1-x, wherein x is between about 0.2 and about 0.8, molar ratio;
- and
- depositing a third layer comprising silicon and germanium by epitaxial deposition on the second layer comprising silicon and germanium, wherein the third layer comprising silicon and germanium has a formula SiyGe1-y, wherein y is between about 0 and about 0.9, molar ratio.
A method of preparing a multilayer structure, the method comprising:
- etching a silicon layer of a silicon-on-insulator substrate, wherein the silicon-on-insulator substrate comprises (i) a single crystal semiconductor handle layer comprising two major, generally parallel surfaces, one of which is a front surface of the single crystal semiconductor handle layer and the other of which is a back surface of the single crystal semiconductor handle layer, a circumferential edge joining the front and back surfaces of the single crystal semiconductor handle layer, a central plane between and parallel to the front surface and the back surface of the single crystal semiconductor handle layer, a central axis perpendicular to the central plane, and a bulk region between the front and back surfaces of the single crystal semiconductor handle layer, (ii) a dielectric layer in interfacial contact with the front surface of the single crystal semiconductor handle layer, and (ii) the silicon layer in interfacial contact with the dielectric layer, and further wherein the silicon layer is etched to a thickness between about 0.5 nanometer and about 4 nanometers, as measured along the central axis;
- depositing boron on the etched silicon layer at a temperature and for a duration sufficient to cause boron atoms to diffuse to the interface between the dielectric layer and the silicon layer;
- and
- depositing a layer comprising silicon and germanium by epitaxial deposition on the etched silicon layer.
Dependencies are inferred from the claim text.