Control of gas phase reactions in low pressure chemical vapor deposition film formation process

研究了低压电离CVD成膜工艺。采用紫外/光电子发射法和电晕放电法作为低压离子源。以正硅酸乙酯(TEOS)/O_3电离混合物为原料制备了四乙基硅酸乙酯(TEOS)/O_3 LPCVD薄膜，并对其形貌进行了观察，探讨了电离对薄膜形成的影响。得到以下结果：(1)建造了冷壁式低压CXTD反应器。(2)紫外/光电子发射方法采用低压汞灯和KrF准分子激光器作为紫外源，多种金属薄膜作为光电子发射器。(3)在低压汞灯紫外线照射下，Au膜的光电子生成最稳定。(4) KrF准分子激光器作为紫外源时，产生的电子密度较高，但随着时间的推移，电子密度迅速降低。(5)在低压汞灯下利用Au薄膜的光电子发射制备TEOS/O_3 LPCVD薄膜，薄膜生长速率提高了20%。(6)研制了一种利用电晕放电将高密度离子送入低压腔的声波射流电离器。(7)声波射流电离器产生的离子密度大于10^<10> cm^<-3>。(8)采用声波射流电离器制备TEOS/O_3 LPGVD薄膜时，薄膜生长速度提高了10倍，薄膜的间隙填充性和衬底依赖性得到改善，但没有出现流动形态。

The low-pressure ionization CVD film formation process was developed. The UV/photoelectron emission and corona discharge methods were used as the ion source at low pressures. Tetraethylorthosilicate (TEOS)/O_3 LPCVD films were prepared from ionized TEOS/O_3 mixtures and their morphologies were observed to investigate effects of ionization on film formation. Following results were obtained.(1)The cold wall type low-pressure CXTD reactor was built.(2)For UV/photoelectron emission method, a low pressure mercury lamp and a KrF excimer laser were used as a UV source and metals films of many kinds were used as a photoelectron emitter.(3)When a Au film was irradiated by UV rays from a low pressure mercury lamp, the photoelectron generation was most stable.(4)When a KrF excimer laser was used as a UV source, the electrons generated with high density but the density reduced quickly with time.(5)When TEOS/O_3 LPCVD films prepared using photoelectron emission from Au film by a low pressure mercury lamp, the film growth rates increased 20%.(6)A sonic-jet ionizer using corona discharge was developed to feed the high density ions to low pressure chamber.(7)The ion density produced by the sonic-jet ionizer was more than 10^<10> cm^<-3>.(8)When TEOS/O_3 LPGVD films were prepared using the sonic-jet ionizer, the film growth rates increased 10 times and the gap filling and substrate dependence of films were, improved but the flow shape did not appear.