Abstract
A method of forming embedded micro channels includes the steps of:(a)forming a negative resist layer on a substrate;(b)using a first light source to expose the negative resist layer through a first mask layer to reach a first depth to form a first exposed portion; (c)using a second light source to expose the negative resist layer through a second a second mask layer to reach a second depth to form a second exposed portion, wherein the second depth is smaller than the first depth and a wavelength of the second light source is smaller than a wavelength of the first light source; and (d)removing a portion of negative resist layer exclusive of the first exposed portion and the second exposed portion to form a micro channel.