If it's really just van der Waals, there is not much of a mechanism there. Van der Waals forces work the same for all materials, just with different intensities for different material polarizabilities. If you want a full derivation of the dispersion force, you can check out
Book Concepts in Surface Physics
For a general overview of all van der Waals forces (Keesom, Debye, London) see e.g.
Article Physics and Chemistry of Interfaces. By Hans-Jürgen Butt, Ka...
If you weren't asking about the function of van der Waals in general, but about the process, please check out the papers of my former colleague Thomas Gerrer:
Article 3 GHz RF measurements of AlGaN/GaN transistors transferred f...
Article Transfer of AlGaN/GaN RF-devices onto diamond substrates via...