Many Xbox 360 parts are the result of work by multiple suppliers. For example the graphics and memory controller (also known as the northbridge) is designed by ATI in Canada.
However all actual manufacturing is handled in Taiwan, starting with Phoenix Precision Technology, which is reported to be making the substrate, the basic material on which chips are built.
Taiwan Semiconductor Manufacturing Co then fabricates the chips. The company will turn out about 20,000 12-inch wafers, each packed with hundreds of chips, during the fourth quarter.
Finally, the wafers are trucked a short distance to Advanced Semiconductor Engineering Inc. ASE separates the chips, packages them in a form suitable for mounting on a printed circuit board, and tests them, before sending them on to Wistron or other contract manufacturers.