Patent Number: 7,825,447

Title: MOS capacitor and semiconductor device

Abstract: A capacitor capable of functioning as a capacitor even when an AC voltage is applied thereto is provided without increasing the manufacturing steps of a semiconductor device. A transistor is used as a MOS capacitor where a pair of impurity regions formed on opposite sides of a channel formation region are each doped with impurities of different conductivity so as to be used as a source region or a drain region. Specifically, assuming that an impurity region that is doped with N-type impurities is referred to as an N-type region while an impurity region that is doped with P-type impurities is referred to as a P-type region, a transistor is provided where a channel formation region is interposed between the N-type region and the P-type region, which is used as a MOS capacitor.

Inventors: Kato; Kiyoshi (Atsugi, JP), Shionoiri; Yutaka (Isehara, JP)

Assignee: Semiconductor Energy Laboratory Co., Ltd.

International Classification: H01L 29/94 (20060101)

Expiration Date: 2019-11-02 0:00:00