Claims
- 1. A manufacturing method of a semiconductor device including a PN junction diode and a control transistor, said PN junction diode functioning as a photo diode and comprising a semiconductor of a first conduction type that is one of a P- and an N-type and another semiconductor of a second conduction type that is the other of the two types, said control transistor controlling transfer of a light signal carrier generated within said PN junction diode, said manufacturing method comprising the steps of:forming a gate oxide film and a gate electrode on a surface of a first conduction type substrate adjusted for said first conduction type; forming a concave portion in a region of said first conduction type substrate, said region being contiguous to said gate electrode; forming on said first conduction type substrate a second conduction type drain region on the opposite side of said gate electrode from said concave portion; implanting second conduction type impurities into said first conduction type substrate at a first angle relative to the substrate in order to form a second conduction type region which includes a region underneath said concave portion and which is provided in a partially submerged manner underneath said gate oxide film; and implanting first conduction type impurities into said first conduction type substrate at a second angle relative to the substrate in order to form a first conduction type region which includes a region underneath said concave portion and which covers said second conduction type region, said first conduction type region and said second conduction type region together constituting said PN junction diode.
- 2. The manufacturing method according to claim 1, wherein said step of forming said concave portion includes the steps of:covering said surface of said first conduction type substrate with a protective film having an opening where said concave portion is to be formed; performing field oxidation on said first conduction type substrate covered with said protective film; and removing said protective film and an oxide layer formed by said field oxidation.
- 3. The manufacturing method according to claim 1, wherein said step of forming said concave portion includes the steps of:forming on said surface of said first conduction type substrate a photo resist film having an opening where said concave portion is to be formed; etching said first conduction type substrate using said photo resist film as a mask; and removing said photo resist film.
Priority Claims (1)
Number |
Date |
Country |
Kind |
11-180440 |
Jun 1999 |
JP |
|
Parent Case Info
This application is a division of Ser. No. 09/452,148 filed Dec. 1, 1999 now U.S. Pat. No. 6,278,145.
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