A group at NIST reports that they have created single electron transistors in a CMOS process. These are meant to support electrometry, thermometry, and quantum information processing. As experimental devices, they are rather large but they do work over temperatures ranging from 30 mK to 300 K. The nanowire and gates at the heart of the devices were formed by e-beam lithography in HSQ and chlorine etch.
Details may be found on the arXiv as arXiv:1206.2872v1.