1997 年 10 巻 4 号 p. 561-569
This paper describes the properties of our new alicyclic-methacrylate polymer, poly(carboxy-tetracyclo[4.4.O.12, 5.17, 10]dodecyl methacrylate) (poly(CTCDDMA)), which was designed as a base polymer for the resist for ArF excimer laser lithography. The etching rate of the polymer for chlorine plasma was 1.15 times that for a novolac-based resist, indicating a higher etching durability than that of poly(p-vinylphenol).
We also studied the adhesion properties of an alicyclic-methacrylate polymer by estimating the work of adhesion using poly(carboxy-tricyclo[5.2.1.02, 6]decylmethyl methacrylate) (poly(CTCDMA)). We found that the adhesion decreased with an increase in the protection ratio for the polymer, and 60% tert-butyl protection caused stripping and collapse of the resist pattern in the standard developer, 2.38% tetramethylammonium hydroxide (TMAH) aqueous solution. We obtained appropriate adhesion using a diluted TMAH aqueous solution as a developer and found that a proper developer-concentration could be determined using the work of adhesion of a polymer. Additionally, we confirmed that introducing a _??_20% hydroxy-tricyclodecyl(meth)acrylate (TCD(M)AOH) unit into the polymer raised the work of adhesion to 74.0mN/m, which was higher than that of the novolac-based resist (73.5mN/m). This made possible the pattern resolution of a poly(CTCDMA)-based resist in the standard developer. We obtained a 0.35-μm pattern using a resist based on a terpolymer containing TCDAOH and the standard developer.
The chemically amplified resist composed of a 33% ethoxyethyl-protected poly(CTCDDMA) and N-hydroxysuccinimide tosylate resolved a 0.15-μm L&S pattern at a dosage of 21.8mJ/cm2, with an ArF prototype lens (NA=0.55) and using a 0.024% TMAH developer.
