METHOD OF MANUFACTURING A SEMICONDUCTOR DEVICE AND SUCH A SEMICONDUCTOR DEVICE

摘要

The invention relates to a method of manufacturing a semiconductor device (10) with a semiconductor body (1) comprising a semiconductor substrate (2) and a semiconductor region (3), which are separated from each other by means of an electrically insulating layer (4), which comprises a first and a second sub-layer (4A, 4B) which, viewed in projection, are adjacent to one another, wherein the first sub-layer (4A) has a smaller thickness than the second sub-layer (4B), and wherein, in a first sub-region (3A) of the semiconductor region (3) lying above the first sub-layer (4A), at least one digital semiconductor element (5) is formed and, in a second sub-region (3B) of the semiconductor region (3) lying above the second sub-layer (4B), at least one analog semiconductor element (6) is formed. According to the invention, the second sub-layer (4B) is formed in such a way that the lower border thereof is recessed in the semiconductor body (1) in relation to the lower border of the first sub-layer (4A). In this way, the formation of so-termed FD (= Fully Depleted) SOI devices (10) is made easy. Preferably, the sub-layers (4A, 4B) are formed using a thermal oxidation that is locally enhanced or retarded (prevented). The semiconductor region (3) is preferably formed by using a substrate transfer technique.