Demonstrating next-generation CD uniformity with today's tools and processes

It is now a widely held opinion that the current and projected reticle CD (critical dimension) uniformity specification demands will continue to task the ability of reticle manufacturers. Similarly wafer lithography tool suppliers are being challenged to demonstrate next generation printing capability in advance of the development of the required reticle manufacturing tools and processes. Although reticle manufacturers are continuing their diligent work in improving CD uniformity, there exists a window of time in which these specification needs for demonstration purposes by the wafer lithography tool developers exceeds those current deans of the broader semiconductor industry. This paper presents an approach to reticle manufacturing for the specific purpose of qualifying an advanced 4X reduction scanner. Typical e-beam reticles written on current generation tools in PBS [Poly(butene-1-sulfone)] resist and wet etched demonstrate CD uniformity of 65 nm - 80 nm expressed as total measured range in both the horizontal and vertical axis across the scanner field of 110 mm by 133 mm. This paper examines methodology employed using PBS and wet etching to generate a demonstration reticle which exhibits such CD range properties. Both reticle properties and wafer results are examined.