Effect of Bias Applied to Hot Wires on Generation of Positive and Negative Charges during Silicon Hot-Wire Chemical Vapor Deposition

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• 作者：Soon Young Park ; Seung Min Yang ; Chan Soo Kim ; Nong Moon Hwang
• 刊名：Journal of Physical Chemistry C
• 出版年：2009
• 出版时间：October 1, 2009
• 年：2009
• 卷：113
• 期：39
• 页码：17011-17017
• 全文大小：373K
• 年卷期：v.113,no.39(October 1, 2009)
• ISSN：1932-7455

文摘

Hot-wire chemical vapor deposition of silicon films has been studied focusing on the generation of electric charge during the process. The currents measured 1.5 cm below the input and output positions, with respect to the DC power supply, of the hot wires at 2000 °C were +4 and −544 nA/cm², respectively, and those 4.5 cm below the input and output positions were +3 and −64 nA/cm², respectively. These data imply that both positive and negative charges are generated presumably by surface ionization of gas molecules on the hot wires, but an appreciable fraction of negative charges was attracted to the electric field around the hot wires, which have the input and output potentials of +18 and 0 V, respectively, provided by the DC power supply. The additional biases of +25 and −25 V applied to the hot wires produced +2.38 and −4.86 × 10⁴ nA/cm², respectively, 1.5 cm below the input position of the hot wires. The absolute value of the current measured under the negative bias is much larger than that under the positive bias. The additional bias on the hot wires significantly affected the amount of charges, which resulted in the change of microstructure, crystallinity, and growth rate of deposited films.