Process for producing semiconductor substrate
AssigneeCanon Kabushiki Kaisha
InventorNobuhiko Sato
Life of this patent
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Abstract
In a process for producing a semiconductor substrate, comprising sealing surface pores of a porous silicon layer and thereafter forming a single-crystal layer on the porous silicon layer by epitaxial growth, intermediate heat treatment is carried out after the sealing and before the epitaxial growth and at a temperature higher than the temperature at the time of the sealing. This process improves crystal quality of the semiconductor substrate having the single-crystal layer formed by epitaxial growth and improves smoothness at the bonding interface when applied to bonded wafers this process enables the detection of the smaller particles on the surface by a laser light scattering method.
Claims32
A process for producing a semiconductor substrate having a non-porous single-crystal layer on a surface of a porous silicon layer comprising, in the listed order, the steps of:
- sealing surface pores of the porous silicon layer to lower its surface pore density;
- heat treating the porous silicon layer at a temperature higher than the temperature in the sealing step;
- and
- epitaxially growing the non-porous single-crystal layer on the surface of the porous silicon layer.
A process for producing a semiconductor substrate comprising, in the listed order, the steps of:
- providing a first substrate having a porous silicon layer on a non-porous silicon substrate;
- sealing surface pores of the porous silicon layer to lower its surface pore density;
- heat treating the porous silicon layer whose surface pores have been sealed at a temperature higher than the temperature in the sealing step;
- epitaxially growing a non-porous single-crystal layer on the surface of the porous silicon layer;
- bonding the non-porous single-crystal layer to a second substrate;
- and
- removing the porous silicon layer so as to leave the non-porous single-crystal layer on the second substrate.
Dependencies are inferred from the claim text.