Mask using polyimide to support a patterned x-ray opaque layer

A process for manufacturing a mask for use in x-ray photolithography starts with the step of coating the first and second sides of a silicon wafer (100) with a boron nitride layer (102). The first side of the wafer (100) is coated with a polyimide layer (104) which serves as a primary x-ray transparent layer for supporting a subsequently deposited x-ray opaque material. The first and second sides of the wafer (100) are then covered with a second boron nitride layer (106). The second side of the wafer (100) is then bonded to a support structure such as a pyrex ring (108). A portion of the first and second boron nitride layers (102, 106) is then removed thus exposing a portion of the underlying silicon substrate (101). The exposed portion of the silicon substrate is then removed thus leaving a ring which supports an x-ray transparent membrane comprising the first boron nitride layer (102), the polyimide layer (104) and the second boron nitride layer (106). The second boron nitride layer (106) is then covered with a patterned layer of x-ray opaque material such as gold. The resulting structure is a mask which uses polyimide as the primary membrane and therefore exhibits enhanced mechanical strength.