Fast, downstream removal of photoresist using reactive oxygen species from the effluent of an atmospheric pressure plasma Jet

Abstract

In semiconductor manufacture photoresist acts as a mask to allow deposition and etching of the substrate in a controlled, localised manner. The photoresist (PR) consists of organic chain molecules that react in the presence of UV light to either harden (negative PR) or soften (positive PR), giving a pattern on the surface where soft PR is etched at a higher rate than hardened PR, leading to preferential etching of the substrate. The photoresist then must be removed to perform the next iteration of etching or deposition, which may happen multiple times for complicated architectures.The standard option to remove the photoresist is to use a low-pressure oxygen plasma discharge in a process

Applications of the COST Plasma Jet: More than a Reference Standard

“…The removal of photoresistant polymers (or plasma etching) between the processing steps is used. Commonly, this is done by using low-pressure plasmas, the operation of which is costly and can damage the substrate surface [26,27].…”

“…An alternative to this method was suggested by West et al [27]. Since in the COST jet the applied field is perpendicular to the gas flow, the charged species, including high energy electrons, are largely confined within the jet.…”

Concepts, Capabilities, and Limitations of Global Models: A Review

“…A topical example of this is atmospheric pressure plasmas (APPs) operated in noble gases, with different molecular admixtures included specifically to generate chemically active species. These plasmas are interesting for various applications, such as surface modification, etching, and also biomedical applications . One of the more studied cases is an Ar or He discharge with molecular oxygen (O 2 ) admixture, which is generally modeled using not more than 25 species and 373 reactions to describe the plasma chemistry.…”

Cold Atmospheric Pressure Plasma VUV Interactions With Surfaces: Effect of Local Gas Environment and Source Design

“…They also observe that small admixtures of oxygen decrease this VUV emission significantly. There has also been work published looking at the effect of a single plasma source on plasma ashing of photoresist materials recently . This paper uses a MHz plasma source utilizing He/O 2 mixtures at 3 mm distance from source to substrate.…”