预注入对Si1-xCx合金形成的影响

室温下在单晶Si中注入(0.6—1.5)at%的C原子,部分样品在C离子注入之前在其中注入²⁹Si⁺离子产生损伤,然后在相同条件下利用高温退火固相外延了Si_1-xC_x合金,研究了预注入对Si_1-xC_x合金形成的影响.如果注入C离子的剂量小于引起Si非晶化的剂量,在950℃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Si_1-xC关键词： 离子注入 固相外延 1-xC_x合金')" href="#">Si_1-xC_x合金

THE EFFECTS OF PRE-IRRADIATION ON THE FORMATION OF Si1-xCx ALLOYS

Carbon ions were implanted into crystal Si to a concentration of(06—15)at% at room temperature. Some samples were pre-irradiated with ²⁹Si⁺ ions, while others were not pre-irradiated. Then the two kinds of samples were implanted with ²⁹C⁺ ions simultaneously, and Si_1-xC_x alloys were grown by solid phase epitaxy with high-temperature annealing. The effects of pre-irradiation on the formation of Si_1-xC_x alloys were studied. If the dose of implanted C ion was less than that for amorphizing Si crystals, the implanted C atoms would like to combine with defects produced during implantation, and then it was difficult for Si_1-xC_x alloys to form after annealing at 950℃. Pre-irradiation was advantageous for Si_1-xC_x alloy formation. With the increase of C ion dose, the damage produced by C ions increased. Pre-irradiation was unfavorable for Si_1-xC_x alloy formation. If the implanted C concentration was higher than that for solid phase epitaxy solution, only part of the implanted C atoms form Si_1-xC_x alloys and the effects of pre-irradiation could be neglected. As the annealing temperature was increased to 1050℃, Si_1-xC_x alloys in both pre-irradiated and unpreirradiated samples of low C concentration remained, whereas most part of Si_1-xC_x alloys in samples with high C concentration vanished.