In addition to the tutorial model in the last section of the Introduction to the Semiconductor Module book (Tutorial Model: DC Characteristics of a MOSFET), there are many examples in the Application Libraries. Every example is accompanied by a PDF documentation with step-by-step instructions and useful comments. The examples can be accessed either online (
https://www.comsol.com/models/semiconductor-module) or within the software by going to the File Menu>Application Libraries>Semiconductor Module.