Transfer of a thin layer from a wafer comprising a buffer layer
First Claim
1. A method of preparing a semiconductor wafer, comprising:
- growing a first layer of a first material in a strained state on a matching substrate comprising a matching layer;
growing a second layer of a semiconductor second material, different from the first material, in a relaxed state on the first layer to form a boundary between the first and second layers and to form a composite structure which comprises the matching, first, and second layers, wherein the first and second layers each have substantially the same first lattice parameter;
creating a region of weakness in the matching substrate to facilitate splitting;
splitting the composite structure at the region of weakness into;
an unfinished wafer that includes the second layer, the first layer, and at least a remaining portion of the matching layer, anda handle wafer;
removing the remaining portion of the matching layer from the first layer; and
removing the first layer from the second layer to produce a surface on the second layer that is substantially smooth and of substantially uniform thickness.
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Accused Products
Abstract
A process for producing a structure of a thin layer of semiconductor material obtained from a composite structure donor wafer. The donor wafer includes a lattice parameter matching layer of a matching substrate that advantageously has an upper layer of semiconductor material having a first lattice parameter. A film of semiconductor material having a second, nominal, lattice parameter that is substantially different from the first lattice parameter is strained by the matching layer. A region of weakness is created in the matching substrate to facilitate splitting. A relaxed layer has a nominal lattice parameter that is substantially identical to the first lattice parameter. The relaxed layer is transferred to a receiving substrate. A number of different wafers can be made by this process.
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Citations
27 Claims
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1. A method of preparing a semiconductor wafer, comprising:
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growing a first layer of a first material in a strained state on a matching substrate comprising a matching layer; growing a second layer of a semiconductor second material, different from the first material, in a relaxed state on the first layer to form a boundary between the first and second layers and to form a composite structure which comprises the matching, first, and second layers, wherein the first and second layers each have substantially the same first lattice parameter; creating a region of weakness in the matching substrate to facilitate splitting; splitting the composite structure at the region of weakness into; an unfinished wafer that includes the second layer, the first layer, and at least a remaining portion of the matching layer, and a handle wafer; removing the remaining portion of the matching layer from the first layer; and removing the first layer from the second layer to produce a surface on the second layer that is substantially smooth and of substantially uniform thickness. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26)
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27. A method of preparing a semiconductor wafer, comprising:
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providing a first layer of material in a strained state on a matching substrate that comprises a matching layer, growing a second layer of a semiconductor second material, different from the first material, in a relaxed state on the first layer to form a boundary between the first and second layers and to form a composite structure which comprises the matching, first, and second layers, wherein the first and second layers each have substantially the same first lattice parameter; creating a region of weakness in the matching substrate to facilitate splitting; splitting the composite structure into; an unfinished wafer that includes the second layer and at least a remaining portion of the matching layer, and a handle wafer; removing the remaining portion of the matching layer from the unfinished wafer by selective etching; and removing the first layer from the second layer by selective etching to produce a surface on the second layer.
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Specification