300mm Si外延片表面颗粒缺陷的研究

研究了不同拉晶速率对300 mm硅外延片表面缺陷的影响,SP1(表面激光颗粒扫描仪)测试结果表明:较低的拉晶速率下,外延片表面出现环状颗粒缺陷分布带；较高的拉晶速率下,外延片表面的环形缺陷带消失.利用Femag-CZ软件模拟了不同速率下晶体的生长结果,结合其c；-cv分布图,分析出这种环状分布的颗粒缺陷是由于晶体中间隙原子富集区产生的微缺陷,在外延过程中( 1050℃)聚集长大,从而在界面处造成晶格畸变引起的.随着衬底拉速的降低,间隙原子富集区的面积增大,硅片外延后越容易出现环状分布的颗粒缺陷.因此在单晶拉制过程中,为了避免这种环状缺陷的产生,应适当提高晶体的拉速.

Particle Defects on Epitaxial Surface with 300 mm Si Substrates

SP1 was used to study particle defects on the surfaces of 300 mm epitaxial wafers with substrates of different pulling rates.The results showed that at low pulling rate ring-distribution particle defects were observed while at higher pulling rate the ring-distribution particle defects disappeared.Femag-CZ was used to simulate the growth of crystals under different pulling rates.With the ci-cv distribution diagram got from the simulation,the reason for the particle defects was explained as that interstitial-related defects in the interstitial-rich area assemble to the interface between the epitaxial layer and the substrate which contributed to the deformation of the crystal lattice during the epitaxial process at 1050 ℃.With the decrease of the pulling rate,the interstitial-rich area increased and the particle defects were more likely to appear.To avoid this kind of ring-distribution particle defects higher pulling rate of the crystal was suggested.