Yes, of course, but according to some sources they are made at Sony. The information I referred to is mostly coming to chipworks, who published articles analyzing APS and full size sensors from Canon, Nikon and Sony.
Canon is said to build a fab for 0.18 microns.
On the other hand, I was thinking about the characteristics of the Canon sensors and stated thinking about the read noise being more a problem of the ADC than of sensor and readout preamps. What is your take on this, could it be that the ADCs used are noisy in the low bits? The high ISO performance of Canons is very good, that really indicates that readout noise is good at some stage. According to "sensorgen" site readout noise decreases on Canons at high ISO.
Canon's CMOS sensors for compact cameras are surely made on a design rule smaller than 0.5 micron, so would think that Canon can get access to a suitable fab. for future DSLR sensors if and when it has a need.
But we have wandered of topic! So ...
The future of MF clearly belongs to Pentax, the only MF player with more than one AF point, stabilized lenses, and vaguely accessible pricing.