Well, I'm not sure, but I've always assumed that if they could animate it in Korea, the animation would be of much higher quality.
However, most "American-made" or "Canadian-made" cartoons, such as Adventure Time or Ed, Edd n Eddy, do use Korean animation if that's what you're asking, and it probably isn't what you're asking.
I know this user on SNN who's Korean, I could ask him.
I asked him, he never even heard of the show.
Thus, the mystery continues.