摘要 |
When a bulk silicon substrate and an SOI substrate are used separately, a board area is increased and so it is impossible to reduce the size of a semiconductor device as a whole. On the other hand, when an SOI-type MISFET and a bulk-type MISFET are formed on a same substrate, the SOI-type MISFET and the bulk-type MISFET should be formed in separate steps respectively, and thus the process gets complicated. A single crystal semiconductor substrate and an SOI substrate separated from the single crystal semiconductor substrate by a thin buried insulating film and having a thin single crystal semiconductor thin film (SOI layer) are used, and well diffusion layer regions, drain regions, gate insulating films and gate electrodes of the SOI-type MISFET and the bulk-type MISFET are formed in same steps. Since the bulk-type MISFET and the SOI-type MISFET can be formed on the same substrate, the board area can be reduced. A simple process can be realized by making manufacturing steps of the SOI-type MISFET and the bulk-type MISFET common.
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