| 摘要 |
PURPOSE:To obtain an SOI structure stably by causing particles of poly Si to accumulate on a PSG which is formed by using a reactive gas containing PH3 by more than a specific rate, and then causing them to from single crystals. CONSTITUTION:Si substrates 12 are placed on a base 13 inside a reactive tube 11, and it is heated up to a specified temperature, and SiH4, O2 and PH3 which are adjusted respectively 16-18 (more than 10% of PH3 is caused to be contained) are introduced inside the tube, and a PSG film 21 of desired P density is formed on the substrate 12, and particles of poly Si 22 are overlayed on the film by supplying only SiH4. Next, the layer 22 is caused to melt and recrystallize by irradiation with a CW Ar laser beam 23. At this time, the PSG21 at the base generates softening phenomenon by the increase of P density, alleviates stress at the surface and prevents the generation of crack in recrystallized single crystals 24. This phenomenon takes place when P density is more than 10%. By this composition, an excellent SOI structure can be stably formed and both its quality and yielding can also be improved. |
