SEMICONDUCTOR DEVICE

A semiconductor substrate includes an n-type substrate region, an n-type first semiconductor region and a second semiconductor region disposed at different positions on the n-type substrate region, an n-type buried layer formed on the n-type first semiconductor region and on the second semiconductor region, a p-type third semiconductor region and a p-type fourth semiconductor region formed on the n-type buried layer and spaced apart from each other, and an n-type fifth semiconductor region that reaches an upper surface of the semiconductor substrate from the n-type buried layer. The n-type buried layer, the n-type first semiconductor region, and the n-type substrate region are present under the p-type third semiconductor region and the n-type fifth semiconductor region. A first transistor is formed in an upper portion of the p-type third semiconductor region, and a second transistor is formed in an upper portion of the p-type fourth semiconductor region.