Element fabrication substrate
View Patent ↗A substrate used for fabricating devices thereon includes an insulating film, and a monocrystal Ge thin layer formed on the insulating film in contact therewith, the monocrystal Ge thin layer having a thickness not more than 6 nm. The monocrystal Ge thin layer has a thickness not less than 2 nm and a compressive strain.
1. A method of manufacturing a substrate on which a semiconductor device is fabricated, the method comprising:
forming a monocrystal SiGe layer on a monocrystal Si layer formed on an insulating film; and
thermal-oxidizing the monocrystal Si layer and the SiGe layer at an initial oxidation temperature at a first stage and at a final oxidation temperature lower than the initial oxidation temperature at a final stage to form a Si oxide film on the Si layer and the SiGe layer on a side opposite to the insulating film and to form a monocrystal Ge layer having a compressive strain, wherein the thermal-oxidizing is performed at a temperature not more than a melting temperature of the SiGe layer, and by setting the initial oxidation temperature at a value exceeding 1000° C. and a final oxidation temperature at not more than 900° C. while decreasing the heating temperature gradually.
2. The method according to claim 1 , wherein the thermal-oxidizing is performed to form the monocrystal Ge layer of not less than 4 nm.
3. A method of manufacturing a substrate on which a semiconductor device is fabricated, the method comprising:
forming a monocrystal SiGe layer on a monocrystal Si layer formed on an insulating film; and
thermal-oxidizing the monocrystal Si layer and the SiGe layer at an initial oxidation temperature at a first stage and at a final oxidation temperature lower than the initial oxidation temperature at a final stage to form a Si oxide film on the Si layer and the SiGe layer on a side opposite to the insulating film and to form a monocrystal Ge layer having a compressive strain, wherein the thermal-oxidizing is performed at a temperature not more than a melting temperature of the SiGe layer, and by setting the initial oxidation temperature at a value exceeding 1000° C. and a final oxidation temperature at not more than 850° C. for the Ge layer being less than 3 nm thick while decreasing the heating temperature gradually.
4. The method according to claim 3 , wherein the thermal-oxidizing is performed to form the monocrystal Ge layer of not less than 2 nm.