Oxidation after oxide dissolution
A method for manufacturing a SeOI substrate that includes a thin working layer made from one or more semiconductor material(s); a support layer; and a thin buried oxide layer between the working layer and the support layer. The method includes a manufacturing step of an intermediate SeOI substrate having a buried oxide layer with a thickness greater than a thickness desired for the thin buried oxide layer; and a dissolution step of the buried oxide layer in order to form therewith the thin buried oxide layer. After the dissolution step, an oxidation step of the substrate is conducted for creating an oxidized layer on the substrate, and an oxide migration step for diffusing at least a part of the oxide layer through the working layer in order to increase the electrical interface quality of the substrate and decrease its Dit value.
1. A method for manufacturing a SeOI substrate having a thin working layer made from one or more semiconductor material(s), a support layer, and a thin buried oxide layer between the working layer and the support layer, wherein the method comprises:
manufacturing an intermediate SeOI substrate having an initial buried oxide layer with a thickness greater than a thickness desired for the final thin buried oxide layer;
dissolving part of the initial buried oxide layer in order to form therewith the final thin buried oxide layer;
oxidizing the substrate to create a surface oxidized layer thereon;
diffusing at least a part of the oxide layer through the surface semiconductor working layer by oxide migration in an amount sufficient to increase the electrical interface quality of substrate and decrease its Dit value at the interface between the semiconductor working layer and the buried oxide layer.
2. The method of claim 1 , wherein the oxidizing is conducted at a temperature of between 1100° C. and 1150° C. for less than 30 minutes.
3. The method of claim 1 , wherein the oxidizing comprises an oxide deposition treatment carried out at a temperature below 900° C.
4. The method of claim 3 , wherein after the oxide deposition treatment, a heat treatment is carried out at a temperature between 1100° C. and 1150° C.
5. The method of claim 3 , wherein the oxide deposition treatment is a chemical vapor deposition treatment, a low pressure chemical vapor deposition treatment, an atomic layer deposition treatment, or a plasma enhanced chemical vapor deposition treatment.
6. The method of claim 3 , wherein the oxide deposition treatment is a low pressure chemical vapor deposition treatment, wherein tetraethylorthosilicate is used as a precursor.
7. The method of claim 3 , which further comprises deoxidizing the substrate after the oxide deposition treatment.
8. The method of claim 3 , wherein the working layer prior to the oxidation oxide deposition treatment is thinner than 55 nm.
9. The method of claim 4 , wherein the dissolving of the surface oxide layer is mainly performed on one or more local island(s) of the buried oxide layer due to masking of the substrate surface and at a dissolution rate of above 0.06/sec.
10. A method for improving the interface quality of a SeOI substrate having a thin buried oxide layer, wherein the substrate has undergone an oxide dissolution treatment, which comprises:
oxidizing the SeOI substrate to create a surface oxidized layer thereon;
diffusing at least a part of the oxide layer through the surface semiconductor working layer by oxide migration in an amount sufficient to increase the electrical interface quality of the substrate and decrease its Dit value at the interface between the semiconductor working layer and the buried oxide layer.
11. The method of claim 10 , wherein the oxidizing is conducted at a temperature of between 1100° C. and 1150° C. for less than 30 minutes.
12. The method of claim 10 , wherein the oxidizing comprises an oxide deposition treatment carried out at a temperature below 900° C.
13. The method of claim 12 , wherein after the oxide deposition treatment, a heat treatment is carried out at a temperature between 1100 ° C. and 1150° C.
14. The method of claim 12 , wherein the oxide deposition treatment is a chemical vapor deposition treatment, a low pressure chemical vapor deposition treatment, an atomic layer deposition treatment, or a plasma enhanced chemical vapor deposition treatment.
15. The method of claim 12 , wherein the oxide deposition treatment is a low pressure chemical vapor deposition treatment, wherein tetraethylorthosilicate is used as a precursor.
16. The method of claim 12 , which further comprises deoxidizing the substrate after the oxide deposition treatment.
17. The method of claim 12 , wherein the working layer prior to the oxide deposition treatment is thinner than 55 nm.
18. The method of claim 12 , wherein the dissolving of the surface oxide layer is mainly performed on one or more local island(s) of the buried oxide layer due to masking of the substrate surface and at a dissolution rate of above 0.06/sec.
19. A method for manufacturing a SeOI substrate having a thin working layer made from one or more semiconductor material(s), a support layer, and a thin buried oxide layer between the working layer and the support layer, wherein the method comprises:
oxidizing the SeOI substrate to create a surface oxidized layer thereon; and
diffusing at least a part of the surface oxide layer through the semiconductor working layer by oxide migration in an amount sufficient to provide an SeOI substrate having a Dit value that is lower than 1×10 12 cm −2 eV −1 and a charge mobility that is higher than 500 cm 2 /Vsec.
20. The method of claim 19 , wherein the SeOI substrate is provided by:
manufacturing an intermediate SeOI substrate having an initial buried oxide layer with a thickness greater than a thickness desired for the final thin buried oxide layer; and
dissolving part of the initial buried oxide layer in order to form therewith the final thin buried oxide layer.