| 摘要 |
PURPOSE:To reduce impurity mixing into a film, and to provide a high quality thin film, by introducing another substance reacting with the imprity when forming the film under a reduced pressure condition. CONSTITUTION:When an Si thin film is formed with an optical CVD method using a raw material gas of Si2H6, hydrogen is introduced into the vacuum vessel 5 from a hydrogen gas system 11, and active hydrogen is then produced by irradiating the interior of the vacuum vessel 5, using a light source 3 of a hydrogen discharge lamp with such a wavelength that hydrogen molecules can absorb light to decompose into atoms. In this state, ArF excimer laser light from an optical source 1 which is shaped into wide planar light by an optical system 2, is introduced into the vicinity of the entire surface of a wafer, while Si2H6 gas is introduced from a raw material gas system 10. The Si2H6 gas absorbs the ArF excimer laser light and is decomposed, forming an Si thin film on the substrate 6. Since oxygen remaining in the vessel would couple with active hydrogen atoms and is exhaused out of the vessel 5 by means of a vacuum exhausting system 8, oxygen in the resulted film can be reduced to about 1/20. |
