METHOD AND DEVICE FOR SURFACE TREATMENT

摘要

PROBLEM TO BE SOLVED: To improve anisotropy and prevent the deterioration of selection rate at the etching a fine pattern by repetitively controlling the turning on/off of a high-frequency voltage which is impressed upon a sample and setting the amplitude of the voltage at a sufficiently high level. SOLUTION: Microwave is introduced into a vacuum vessel 104 via a microwave power source 101 through a waveguide 102 and an inlet window 103. An electromagnet 105 is arranged around the vessel 104. Because of the strength of the magnetic field formed by the electromagnet 105, the cyclotron motions of electrons in plasma 106 resonate with the frequency of electromagnetic waves. In order to accelerate ions made incident to a sample 107, a high-frequency bias power source 109 is connected to a sample stage 108. As is indicated in the voltage waveform 110 of the power source 109, the power source 109 is constituted in such a way that a bias voltage can be turned on. The practical frequency of the high-frequency bias voltage is between 200 kHz and 2 MHz. Therefore, anisotropy can be improved, and the selection rate deterioration can be prevented at etching of a fine pattern.