| 摘要 |
PROBLEM TO BE SOLVED: To effectively remove an unnecessary pattern produced in a multiple exposure by performing whole surface etching and surface reforming when a pattern is formed by surface imaging. SOLUTION: A silicon wafer Wa is spin- coated with a resist RE, and for double exposures, the pattern of a reticle A is then transferred to the resist RE and the pattern of a reticle B is then transferred to the same region at the same time. The resist RE is put into contact with a silicon coupling gas over a hot plate at 120 deg.C with a surface reforming apparatus to silylate the surface of the resist. The whole surface of the resist RE is then etched away using a mixed gas of CF4 and O2 under the condition in which the etching rate of a silylated portion is equal to that of a not-silylated portion until an unnecessary portion is etched away. Next, the resist is dry-developed with O2 RIE by using the silylated portion as a mask to obtain an objective pattern. |
