07037788 is referenced by 45 patents and cites 19 patents.

By improving profile of impurity concentration in a channel portion of an FET or an IGBT of a trench gate type, variation of threshold value is lessened, and a destruction caused by current concentration is prevented while suppressing deterioration of cut-off characteristics. An island of a base region of p-type is formed in a semiconductor substrate of n-type by carrying out high acceleration ion implantation twice followed by annealing, so that the impurity concentration profile in a channel portion changes gradually in a depth direction. Accordingly, it is possible to lessen variation of the threshold value and to reduce pinch resistance while at the same time improving sub-threshold voltage coefficient and conductance characteristics.

Title
Manufacturing method of semiconductor device
Application Number
10/786107
Publication Number
7037788 (B2)
Application Date
February 26, 2004
Publication Date
May 2, 2006
Inventor
Takafumi Arakawa
Kariya
JP
Masatoshi Kato
Aichi-gun
JP
Hiroyasu Ito
Nagoya
JP
Agent
Posz Law Group
Assignee
Denso Corporation
JP
IPC
H01L 21/336
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