Method of production of semiconductor device having semiconductor layer and support substrate spaced apart by recess

A semiconductor device production method, comprising

• performing trench etching to form a trench in a thickness direction of a semiconductor layer so that both of a first pattern portion and a second pattern portion whose side walls face each other across the trench are formed, wherein:
• in the trench etching, the semiconductor layer is etched and removed while a protective film is formed on a surface of the semiconductor layer,
• the trench etching is performed so that the first pattern portion and the second pattern portion are configured to have a same potential or a same temperature during the trench etching,
• the trench etching is performed to form the first pattern portion and the second pattern portion so that the first pattern portion and the second pattern portion are electrically isolated from each other after the trench is formed, and
• the trench etching is performed to provide a structure in which a total area of a surface of a trench etching starting side and side walls of the first pattern portion is equal to a total area of a surface of a trench etching starting side and side walls of the second pattern portion.

A semiconductor device production method, comprising

• performing trench etching to form a trench in a thickness direction of a semiconductor layer so that both of a first pattern portion and a second pattern portion whose side walls face each other across the trench are formed, wherein:
• in the trench etching, the semiconductor layer is etched and removed while a protective film is formed on a surface of the semiconductor layer,
• the trench etching is performed so that the first pattern portion and the second pattern portion are configured to have a same potential or a same temperature during the trench etching,
• the trench etching is performed to form the first pattern portion and the second pattern portion so that the first pattern portion and the second pattern portion are electrically isolated from each other after the trench is formed, and
• the first and second pattern portions are subjected to the trench etching in a state where both of a portion of the semiconductor layer configuring the first pattern portion and the semiconductor layer configuring the second pattern portion are joined to and supported on a support substrate through an insulating film at a portion other than a trench forming portion, and
• the trench etching is performed in a state where a joint surface area between the first pattern portion and the insulating film is equal to a joint surface area between the second pattern portion and the insulating film.

A semiconductor device production method comprising

• performing trench etching to form a trench in a thickness direction of a semiconductor layer so that both of a first pattern portion and a second pattern portion whose side walls face each other across the trench are formed, wherein:
• in the trench etching, the semiconductor layer is etched and removed while a protective film is formed on a surface of the semiconductor layer,
• the trench etching is performed so that the first pattern portion and the second pattern portion are configured to have a same temperature during the trench etching, and
• the trench etching is performed to provide a structure in which at least one of the first pattern portion and the second pattern portion has a heat escape portion that releases heat from the at least one pattern portion, so that both of the first pattern portion and the second pattern portion have the same temperature during the trench etching.