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In III–V IC processing, lift-off patterning is universally used. Historically used negative resist has its limitations; hence the image reverse process using positive tone resist has been utilized as the main work horse in lift-off applications. Metal lift-off processes using a specially designed chemically amplified (CAMP) negative tone resist have been evaluated for thin and thick metal layers to have a varying degree of success. Lift-off using CAMP photoresists has made it possible to reduce cycle time (~57% reduction in $1\times$ theoretical cycle time per layer) and reduce cost (due to elimination of steps) as compared to the image reverse process. However, achieving consistent lift-off and critical dimension (CD) control presents challenges, which are discussed in this paper. [ABSTRACT FROM AUTHOR]

In this paper, the evolution of various lithographic processes aimed at fabricating robust tantalum nitride (TaN) resistors in GaAs-based BiFET and BiHEMT technologies are discussed in detail. Such approaches include the common image reverse photograph process (via amine poisoning) using a positive tone resist, the use of a chemically amplified negative tone resist, and also straight patterning of a positive tone resist. The aforementioned approaches were found to have their own unique challenges as it applied to printing robust TaN-based resistors approaching nearly a micron in width which is needed for high density mixed signal designs. We will explore many of these challenges in detail for the various lithography schemes. [ABSTRACT FROM AUTHOR]

The abstract in is incorrect. The word “photograph” was used in error rather than the more correct, “photo.” The abstract should read: In this paper, the evolution of various lithographic processes aimed at fabricating robust tantalum nitride (TaN) resistors in GaAs-based BiFET and BiHEMT technologies are discussed in detail. Such approaches include the common image reverse photo process (via amine poisoning) using a positive tone resist, the use of a chemically amplified negative tone resist, and also straight patterning of a positive tone resist. The aforementioned approaches were found to have their own unique challenges as it applied to printing robust TaN-based resistors approaching nearly a micron in width which is needed for high density mixed signal designs. We will explore many of these challenges in detail for the various lithography schemes. [ABSTRACT FROM AUTHOR]