溫度與過飽和度對液相沈積氧化矽之影響

Abstract

液相沈積氧化矽的品質可藉由化學純化系統和循環沈積系統而提升,這兩 套系統分別針對飽和溶液的配製與液相沈積氧化膜的形成而建立.我們首 先研究液相沈積氧化矽的沈積速率和粒子沈積在膜上的程度.減少外加水 量或降低沈積溫度可降低沈積速率,粒子沈積程度可藉減少外加水量或使 用循環沈積系統來降低.其次,我們探討沈積溫度,外加的水量與飽和氟矽 酸的體積比,以及沈積時間對液相沈積氧化矽特性的影想,這些受氧化矽內 的氟與氫氧基影響的特性包括折射率,密度,紅外線光譜與蝕刻速率.另一 方面,循環沈積系統可改善液相沈積氧化膜的漏電流和崩潰電場分佈,而且 降低沈積時的溫度可獲得更進一步的改善.雖然低電場漏電流隨沈積溫度 而降低,但是中電場時會發生過早的注入電流.最後,液相沈積氧化膜第一 次被應用在場效電晶體的閘極絕緣層,元件的參數被萃取出來而且與各種 沈積氧化矽為閘極絕緣層的場效電晶體做比較,所有的結果存在良好的場 效電晶體特性. The quality of liquid-phase deposited (LPD) oxide was promoted by the chemical purification system and the circulated deposition system, which was established for the preparation of the saturated solution and for the LPD oxide formation, respectively. We first investigated the deposition rate of LPD oxide and the degree of particle precipitated on the film. The deposition rate was reduced by decreasing the addition of H2O or by decreasing the deposition temperature. The degree of particle precipitation was reduced by decreasing the addition of H2O or by using the circulated deposition system. Second, we studied the effects of the deposition temperure, the volume ratio between H2O and the saturated solution, and the deposition time on the LPD oxide characteristics. On the other hand, we found that the circulated deposition system can improve the leakage current density and the breakdown field distribution. Finally, the LPD oxide was applied on the gate insulator of MOSFETs for the first time. The device parameters were investigated and compared with those using various deposited gate insulators.