Advanced photoresist for high density groove-recording disc

It is necessary to reduce the mastering noise, particularly for a groove-recording disc such as the Blu-ray disc. Despite using a deep-UV (DUV) laser, which is the leading method of forming a groove with a narrow track pitch, an improvement of the photoresist is also required. There are some reports which discuss the chemical aspects of photoresist with respect to the ROM disc signal. However, there is no report mentioning the photoresist molecular parameters and the groove noise on the DUV mastering. In this paper, we design the composition of a novolak-type resist, consisting of a base resin and diazonaphthoquinone photoactive compound (PAC), for DUV mastering, and achieve a reduction of the groove noise.