Abstract: According to an embodiment, a wafer holder includes a heat receiving portion, a heating portion, and a contact making portion. The heat receiving portion receives heat from a heat source. The heating portion heats a wafer using the heat received by the heat receiving portion. The contact making portion makes contact with an outer edge of the wafer. A heat-transfer suppressing portion is provided at least either for the contact making portion, or in between the heat receiving portion and the contact making portion, or in between the heating portion and the contact making portion.

Abstract: A method of manufacturing an optical semiconductor element comprises: forming a striped protruding body by selectively dry etching an InGaAlP layer along its thickness, the InGaAlP layer being formed on a substrate; forming a protection film on an upper face and on both side faces of the protruding body; and forming a ridge including the protruding body by etching the InGaAlP layer around the protruding body using a solution containing hydrofluoric acid.

Abstract: A semiconductor thin film manufacturing method includes: forming a semiconductor thin film on a substrate; forming a transcriptional body containing a metal element on a part thereof; bringing a part of the transcriptional body into contact with the semiconductor thin film, and transferring the metal element onto the semiconductor thin film; and fusing the semiconductor thin film and crystallizing the semiconductor thin film using the metal element of the solution as crystal producing nucleuses.

Abstract: A method of manufacturing an optical semiconductor element comprises: forming a striped protruding body by selectively dry etching an along its thickness, the InGaAIP layer being formed on a substrate; forming a protection film on an upper face and on both side faces of the protruding body; and forming a ridge including the protruding body by etching the InGaAIP layer around the protruding body using a solution containing hydrofluoric acid.

Abstract: A semiconductor thin film manufacturing method includes: forming a semiconductor thin film on a substrate; forming a transcriptional body containing a metal element on a part thereof; bringing a part of the transcriptional body into contact with the semiconductor thin film, and transferring the metal element onto the semiconductor thin film; and fusing the semiconductor thin film and crystallizing the semiconductor thin film using the metal element of the solution as crystal producing nucleuses.

Abstract: A semiconductor thin film is manufactured by forming a first foundation layer on a substrate; making recesses in and raised parts on the first foundation layer; forming a second foundation layer on the first foundation layer, the second foundation layer extending over the recesses and raised parts of the first foundation layer, having heat conductivity which is different from heat conductivity of the first foundation layer, and having a flat surface; forming a semiconductor thin film on the second foundation layer; and illuminating energy beams onto the semiconductor thin film, and crystallizing the semiconductor thin film using the recesses and the raised parts of the first foundation layer and a part of the second foundation layer as crystal producing nucleuses.