| 摘要 |
<p>PROBLEM TO BE SOLVED: To form a protecting film without pinholes, by forming an oxide film on a silicon film formed on the insulating film of a substrate, performing patterning and removing the oxide film. SOLUTION: At first, a ground film 12 of silicon oxide with a thickness of 2000Åis formed by sputtering method on a substrate 11. Then, an intrinsic (I type) amorphous silicon film 13 having a thickness of 500-1500Å, e.g., a 1000Å, is formed by a plasma CVD method. Furthermore, a silicon oxide film 14 having a thickness of 1000Åis formed as a protecting film in crystallizing annealing by the plasma CVD method. Thereafter, the aqueous solution of 1/100HF and ammonium fluoride (1/10BH F) is used as etchant, the silicon oxide film 14 is removed and the surface of the silicon film is exposed. Then, the silicon film is patterned by well-known photolithography, and an island- shaped silicon film 17 is obtained. On the upper surface of this silicon film, a silicon oxide film 16 obtained by the previous thermal oxidation is tightly attached. Thereafter, 1/100HF solution is used, and the silicon oxide film 16 is etched.</p> |
