| 摘要 |
PURPOSE:To execute an etching operation whose etching speed is fast, without etching residue and whose selective ratio with respect to a resist is high by a method wherein a substance containing In or Sn is etched by using a gas containing ketones or hydrocarbons. CONSTITUTION:A substance whose main constitutive element is In or Sn is etched by a low-temperature plasma using a gas containing ketones expressed by a chemical formula of R1CoR2 or containing a hydrocarbon having a methyl group. In this formula, R1 and R2 are alkyl groups. These substances are decomposed in the plasma; CH3 and H are generated in large quantities; accordingly, a reaction with the substance containing In or Sn is caused easily, and an etching operation progresses. Because the ratio of hydrogen and oxygen to carbon in an etching gas is small as compared with alcohols, a reaction to generate a carbon-based polymer is caused on a resist; accordingly, an etching operation of the resist is suppressed and a selective ratio with respect to the resist is enhanced. It is preferable to contain O2 in a range of 5-0.5 for C/O. Because the etching operation is executed in a high vacuum, a reaction product is easy to gasify, and an etching residue is hardly produced. The degree of vacuum is preferably to be 50mTorr or below. |
