摘要 |
At an element formation surface side of a p-type Si substrate, a digital circuit and an analog circuit are provided. The analog circuit includes a p-type well and n-type wells formed at the element formation surface side of the p-type Si substrate. The analog circuit includes a deep n-type well located closer to the bottom side of the p-type Si substrate than the p-type well, so as to isolate the p-type well from a bottom-side region of the p-type Si substrate. The deep n-type well includes a first deep n-type well. The deep n-type well includes a second deep n-type well located closer to the bottom side of the p-type Si substrate than the first deep n-type well, and having an n-type impurity concentration, which is different from the first deep n-type well.
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