关键词: 硅外延缺陷, 背圈, 晶圆背圈, ASME2000外延炉

Abstract: During the production of silicon epitaxial wafers in the ASM E2000 epitaxial furnace, abnormal back-ring phenomena sometimes appear on the backside of wafers, including abnormal back-ring size, abnormal back-ring shape, and back-ring eccentricity. It is found that back-ring phenomena only occurs on wafers with non-silicon dioxide back seals. For the generation of abnormal back-ring, experimental verification of relevant parameters such as slide, airflow, temperature and time is carried out to obtain the reasons for the formation of back-ring and the reasons for the generation of abnormal back-ring. Wafers will form the back-ring after baking at 900 ℃ for 60 s, which is a normal phenomenon in the epitaxial process, but the irregular back-ring is usually accompanied by the synchronization deterioration of other epitaxial process parameters. The abnormal back-ring can be solved by adjusting the process parameters, equipment slips, skips, and the replacement of graphite parts.

Key words: silicon epitaxial defects, back-ring, wafer back-ring, ASM E2000 epitaxial furnace