According to Intel, the Xe "DG1" GPU will be made on the company's own 10nm process. It's believed that the firm will outsource the production of the Xe "DG2" GPU to TSMC because the latter can produce the chips faster and more economically.
Previously, Intel's official communication indicates that a future Xe would be one of the first parts to use the company's internal 7nm process. It's unknown whether Intel's plans have changed, or whether TSMC will only make certain variants.
Via: El Chapuzas Informático