Postexposure bake delay stability

The main immersion-specific lithography defects reported in the literature fall into these general types particles, bubbles, water marks, extra patterns, resist residues, line thinning and swelling, bridging, B ARC blobs, and aerosols. Although the nature, origins, formation mechanisms, and effects of immersion defects 

Okoroanyanwu, R. Kirsch, R. Wirtz, M. Grundkowski, and W. Grundke, Defect metrology in water immersion lithography, Semiconductor Fabtech (Nov. 2007). 

Bubbles are typically spherical. Their overall impact on imaging is dependent on their location relative to the surface of the resist. Bubbles close to the resist surface cause underexposure and nonexposure of the patterns in the area under the bubble. They may also be associated with local magnification (swelling) 

Photoresist outgassing a potential achilles heel for short wavelength optical lithogra phy, Proc. SPIE 5376, 1 15 (2003). 

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