| 摘要 |
PURPOSE:To form polycrystalline silicon having large particle diameters in a low temperature process so that particle diameter distribution in the surface of a polycrystalline silicon film is uniform with good reproducibility by forming in advance a mask on a nonsingle crystalline silicon and selectively implanting silicon ions. CONSTITUTION:A thermal oxide film 2 is formed on a P-type silicon substrate 1, and a polycrystalline silicon thin film 3 is further formed by a vacuum depositing method. Then, an SiO2 film is formed by a normal pressure CVD method on the film 3. With a resist pattern as a mask the SiO2 film is etched with buffer fluoric acid (1%) to obtain a quasi-conical SiO2 pattern 4. Thereafter, with the pattern as a mask silicone ions are implanted into the film 3. Then, after the pattern 4 is completely removed with fluoric acid (2.5%), it is annealed in a furnace at 550 deg.C in a nitrogen atmosphere, and the film 3 which become amorphous is again crystallized with the region which has not been subjected to ion implantion as a nucleus. Thus, a polycrystalline silicon film which has large particle size and uniform particle diameter distribution in the surface can be formed.
|
