| 摘要 |
<p>PURPOSE:To shorten the etching time in a contact layer forming process by a method wherein a base insulating film, on which hydrogen content is adjusted, is formed and hydrogen plasma etching and the deposition of semiconductor are repeated alternately. CONSTITUTION:A contact layer 28 is formed on a source electrode 27s and a drain electrode 27d using a selective growth method, Etching treatment is conducted for forty-seven seconds using hydrogen plasma. When deposition treatment is conducted, silicon is deposited by flowing SiH4 and PH3 for three seconds at the flow rate of 25sccm and 150sccm respectively in a hydrogen plasma atmosphere. The above-mentioned deposition and etching treatments are regarded as one cycle, and by repeating 30 cycles, an N<+> type micro crystal silicon film (contact layer 28) is formed on the source electrode 27s and the drain electrode 27d. When the hydrogen content of the base insulating film 26 of the source-drain electrode is increased, the quantity of hydrogen going into the base insulating film 26 becomes small, and etching rate becomes larger. As a result, the time of etching cycle can be cut down.</p> |
