US Patent 10475885 Semiconductor substrate structures and semiconductor devices

A semiconductor substrate structure includes a semiconductor substrate (P-type), a first buried well region (N-type) disposed in the semiconductor substrate, a first buried layer (N-type) and a second buried layer (P-type) disposed in the semiconductor substrate and on the first buried well region. The first buried layer has a first portion and a second portion. The second buried layer is located between the first portion and the second portion. A top surface of the first portion, a top surface of the second buried layer, and a top surface of the second portion are level with a top surface of the semiconductor substrate, a sidewall of the first portion is aligned with a sidewall of the first buried well region, and a sidewall of the second portion is aligned with another sidewall of the first buried well region. A semiconductor device includes the semiconductor substrate structure and an epitaxial layer.