C离子注入Si中Si-C合金的形成及其特征

Si_(1-x )C_x Alloy Formation and It s Characteristics After Carbon Ion Implantation in Silicon

利用离子注入和高温退火的方法在 Si中生长了 C含量为 0 .6 %— 1.0 %的 Si1 - x Cx 合金 ,研究了注入过程中产生的损伤缺陷、注入 C离子的剂量及退火工艺对合金形成的影响 ,探讨了合金的形成机理及合金产生的应变分布的起因 .如果注入的 C离子剂量小于引起 Si非晶化的剂量 ,退火过程中注入产生的损伤缺陷容易与 C原子结合形成缺陷团簇 ,难于形成 Si1 - x Cx 合金 ,而预先利用 Si离子注入引进损伤有利于 Si1 - x Cx 合金的形成 ;但如果注入的C离子可以引起 Si的非晶化 ,预先注入产生的损伤缺陷不利于 Si1 - x Cx 合金的形成 .与慢速退火工艺相比 ,快速热退火工艺有利于 Si1 - x Cx 合金的形成 .离子注入的 C原子在空间分布不均匀 ,退火过程中将形成应变不同的 Si1 - x-Cx 合金区域 .

Si 1-x C x alloys with carbon concentration of 0 6%-1 0% are formed by means of ion implantation and high temperature annealing.The effects of radiation damage,implanted carbon ion doses and annealing techniques on the formation of Si 1-x C x alloy s are studied.The formation mechanism of alloy and the characteristics of the strain distribution are also discussed.If the implanted carbon dose i s less than that to form an amorphous Si layer,the implanted carbon atoms will incline to combining with the defects produced during the carbon implantation th at the defect clusters are formed.It was difficult to form Si 1-x C x alloys during the high temperature annealing.Damage introduced by Si ion pre -implantation to form an amorphous region is beneficial to the formation of Si 1-x C x alloys.If the damage produced during the more carbon ion i mplantation is large enough to form an amorphous Si layer,the pre-implantation of Si ions will introduce more defects that are difficult to annihilate.Thus,the pre-implantation is disadvantagous for the formation of Si 1-x C x alloys.Compared with the two-step annealing method,rapid annealing is favora ble to the formation of Si 1-x C x alloys due to the existence of m ore vacancy positions for carbon atoms.The heterogeneous distribution of implant ed C atoms results in the formation of regions with different strain,which can b e observed with X-ray diffraction.