Method for manufacturing SOI substrate and method for manufacturing semiconductor device

A method for manufacturing an SOI substrate comprising the steps of:

• forming a single crystal semiconductor layer over a first single crystal semiconductor substrate by an epitaxial growth method;
• performing a first thermal oxidation treatment on the first single crystal semiconductor substrate over which the single crystal semiconductor layer is formed to form an oxide film at least on a surface of the single crystal semiconductor layer in an atmosphere containing hydrochloric acid;
• irradiating the single crystal semiconductor layer with ions mainly containing H3+ through the oxide film to form an embrittled layer in the single crystal semiconductor layer;
• bonding the single crystal semiconductor layer formed over the first single crystal semiconductor substrate and a second semiconductor substrate with the oxide film interposed therebetween;
• separating the single crystal semiconductor layer and the second semiconductor substrate from the first single crystal semiconductor substrate at the embrittled layer by a first heat treatment to obtain the first single crystal semiconductor substrate and the second semiconductor substrate to which the separated single crystal semiconductor layer is bonded;
• performing a planarization treatment on the single crystal semiconductor layer which is bonded to the second semiconductor substrate;
• performing a second thermal oxidation treatment on the single crystal semiconductor layer after the step of performing the planarization treatment,
• wherein irradiating the single crystal semiconductor layer with ions to form an embrittled layer is performed only once during the method for manufacturing the SOI substrate, and
• wherein the first thermal oxidation treatment is performed so that chlorine is contained in a region of the oxide film at a concentration ranging from 1×1016/cm3 to 5×1021/cm3.

A method for manufacturing a semiconductor device comprising the steps of:

• forming a single crystal semiconductor layer over a first single crystal semiconductor substrate by an epitaxial growth method;
• performing a first thermal oxidation treatment on the first single crystal semiconductor substrate over which the single crystal semiconductor layer is formed to form an oxide film at least on a surface of the single crystal semiconductor layer;
• irradiating the single crystal semiconductor layer with ions mainly containing H3+ through the oxide film to form an embrittled layer in the single crystal semiconductor layer;
• bonding the single crystal semiconductor layer formed over the first single crystal semiconductor substrate and a second semiconductor substrate with the oxide film interposed therebetween;
• separating the single crystal semiconductor layer and the second semiconductor substrate from the first single crystal semiconductor substrate at the embrittled layer by a first heat treatment to obtain the first single crystal semiconductor substrate and the second semiconductor substrate to which the separated single crystal semiconductor layer is bonded;
• performing a planarization treatment on the single crystal semiconductor layer which is bonded to the second semiconductor substrate;
• performing a second thermal oxidation treatment on the single crystal semiconductor layer after the step of performing the planarization treatment;
• and
• forming a gate electrode over the single crystal semiconductor layer with a gate insulating layer interposed therebetween,
• wherein irradiating the single crystal semiconductor layer with ions to form an embrittled layer is performed only once during the method for manufacturing the semiconductor device,
• wherein metal ions are introduced in the irradiating step, and
• wherein the oxide film is formed thicker than depths at which the metal ions are introduced in the irradiating step.