Application of chemically amplified resist to 10-keV e-beam system

Abstract

Chemically amplified resists (CAR) which are widely used in KrF lithography are recently employed to e-beam mask making for its high sensitivity and high performance. The high sensitivity of CAR is attractive in a 50keV variable shaped e-beam system for reducing heating effect and improving throughput problems. As the device shrinkage is accelerated, superior mask process has highly been requested in the 10keV system as well. To cope with these requests, the feasibility of a CAR in a 10keV e-beam system has been investigated through comparison with a typical resist for 10keV, PBS. The difference of each resist potentiality between CAR and PBS results in a contrast superiority. As CAR uses an aqueous developer, the development induced error can be reduced owing to its good develop stability and a high evaporation heat. As a result, more accurate CD control can be achieved. The CD linearity and dose margin with the CAR are comparable to or better than those with the PBS. It is concluded that the CAR has various advantages over PBS and can supersede the PBS in a 10keV e-beam system.