| 摘要 |
PURPOSE:To obtain an element excellent in the gate oxide film quality, by a method wherein both oxygen and hydrogen radicals are formed and applied to the surface of an element. CONSTITUTION:A group A of substrates of P type Si (10.0) and with a resistivity of 6-8OMEGAcm are placed in a quartz beaker and boiled in a mixed solution of sulfuric acid and hydrogen peroxide and are then rinsed. A group B of substrates are placed in a cassette, which is set in a wafer loading chamber 3. In a processing chamber, H2 gas is introduced at a flow rate of 100ml/min and maintained at about 100Torr. Ultraviolet rays are applied from the upper part of the processing chamber using a 500w Hg lamp to form hydrogen radical, which is applied to the Si substrate surfaces. Then, 2,520 sheets of Si wafers are introduced into a furnace and oxidized in an O2 gas flow at 1,000 deg.C to form a thermal oxide film 26 of 400Angstrom on each of the wafers. A resist pattern 28 is formed on each wafer using a positive-type photoresist. A CF4/O2 mixed gas (with a flow rate ratio of 1:1, 50ml/min) is introduced into a cylindrical plasma etching apparatus to etch a polycrystalline Si film 27 under a condition of an RF electric power of 200w. Thereafter, the resist film 28 is removed by boiling each wafer in a mixed solution of sulfuric acid and hydrogen peroxide. |
