Solventless Polyimide As Patterning Agent
Original Publication Date: 1985-Feb-01
Included in the Prior Art Database: 2005-Feb-18
This article relates generally to a photolithographic process and more particularly to the use of polyimide as an aid in better defining edges of a protective covering for circuit formation. Still more particularly, it relates to a lithographic process which utilizes polyimide as part of the photoresist process such that the photoresist is patterned and used as a resist stencil to allow etching, with controlled undercoat, of the underlying layer of solventless polyimide. Improved edge definition of a protective coat can be obtained by combining polyimide with photoresist to form the pattern for etching. In the process, a vacuum technique is used to deposit solventless polyimide onto silicon with two monomers. The evaporation rates of the monomers are controlled to obtain precise stoichiometry and high deposition rates.