While it's generally true that a larger sensor can produce better image quality through larger pixels, less image noise and a wider dynamic range, the lens used will arguably show a more appreciable difference in quality when you're comparing crop-frame sensors from Canon and Nikon since the sensor sizes are very close. It may be an extreme comparison but a cheap, not so optically-sharp lens with 10x zoom used on the D90 will probably produce lower quality images than an expensive, sharp prime lens used on a 600D.
Canon's APS-C crop-frame sensors are all smaller than Nikon's own, so no, there is no Canon DSLR whose sensor is the same size as that in the D90.
DSLRs: Canon EOS 7D Mark II, Canon EOS 70D
CSC: Canon EOS M3
Lenses: Canon EF-S 15-85mm f/3.5-5.6 IS USM, EF 50mm f/1.8 II, EF 100-400mm f/4.5-5.6L IS USM, Canon EF-M 18-55mm f/3.5-5.6 IS STM, Canon EF-M 22mm f/2.0 STM