With SX AR-N 7730/37, we present a new negative CAR e-beam resist. This resist possesses a very high sensitivity with at the same time high process stability. The stability of solutions and layers could thus be considerably improved.

Some time ago, we reported on the development of a highly sensitive e-beam resists SX AR-N 7700/37. One problem in the past was the too low resolution of only 300 nm. The resolution could now be significantly improved, while all other positive properties were maintained.

Process parameters:

Film thickness:                                   120 nm

Soft bake:                                              85 °C

Sensitivity (20 kV):                            3.38 µC/cm²

Crosslinking bake:                            105 °C, 2 min hotplate

Developer:                                            AR 300-47 (2.5 : 1 diluted)

Fig. 1:  Minimum resolution of 50 nm with e-beam resist SX AR-N 7700/37

A resolution of 50 nm is a very good result for a chemically amplified resist with a sensitivity of 3 µC/cm². The precision of the edges however leaves still much to be desired, as demonstrated in the figure. Intended is thus to now improve the structural quality by further modifications of the resist formulation and an optimisation of the manufacturing process to render the resist suitable for industrial applications like e.g. for mask production.