Swelling cross-linking negative resists

Both solvent-iaduced swelling and oxygen inhibition ate characteristic of all cross-linking negative resists based on free-radical chemistry. 

Two types of resists are used negative and positive resists. Negative resists have a chemically inert polymer component, such as mbber, and a photoreactive agent that reacts with light to form cross-links in the mbber. When placed in an oiganic developer solvent, the unexposed, unpolymerized resist dissolves, leaving a polymeric pattern in the exposed regions. Because the polymer swells in the solvent, the resolution is limited to two to three times... 

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