Patent ID: 8017505

Claim:
A method of manufacturing a semiconductor device, comprising: a) forming a SiGe layer on a substrate; b) forming a Si layer on the SiGe layer; c) forming a groove that exposes a side surface of the SiGe layer by partly and sequentially etching a supporting member, the Si layer, and the SiGe layer; and d) forming a hollow portion between the substrate and the Si layer by etching the SiGe layer from the groove, step d) includes: forming a first part of the hollow portion by supplying a first etching liquid to the groove; removing a second etching liquid from the first part of the hollow portion, the first etching liquid changing to the second etching liquid after the first part being etched; forming a second part of the hollow portion by supplying a third etching liquid to the first part of the hollow portion; and removing a fourth etching liquid from the second part of the hollow portion, the third etching liquid changing to the fourth etching liquid after the second part being etched, wherein the first etching liquid and the third etching liquid including a fluorinated nitric acid solution that has not generated nitrous acid within itself due to etching the SiGe layer or includes an extremely low concentration of nitrous acid due to etching the SiGe layer, and wherein the fluorinated nitric acid solution includes HNO 3 and H 2 O, where the HNO 3 and H 2 O volume ratio to HF is more than or equal to fifty times.