P型氮化鎵薄膜之熱處理效應研究

Abstract

中文摘要 本論文主要是探討氮化鎵p型鎂雜質摻雜樣品在不同的熱處理溫度及時間光電物理行為的影響。冷激光量測光譜顯示隨著鎂摻雜量的增加分別出現兩個主導的波峰，其一為電導帶至鎂所形成受子能階之能量躍遷eA(385nm)，在高摻雜的樣品同時又會出現一個較寬的DAP(430nm)波峰，這有可能是鎂的錯合物所造成的深能階施子躍遷至受子能態的發光光譜。 由霍爾電性量測結果，我們發現在700℃熱處理的電性結果遠較高溫為優。最佳電性結果其分別為:電阻率∼0.33Ω-cm、電洞濃度∼2×1018cm-3以及電洞遷移率∼10cm2/V.s，顯示高達十分之一的Mg經由熱處理過程被活化，此結果與世界知名的日亞公司極為接近。

Abstract We have investigated the optical and electrical properties of magnesium doped GaN films under various doping level and thermal annealing process. Photoluminescence data reveals that once the Mg is added there shows that a conduction band to acceptor (eA) transition peaked at 385nm for nearly the entire range of Mg-doped samples. When more Mg is doped , a broader blue 430nm feature is also observed, which , we believe, is associated with a DAP transition involving with deep donors introduced by the high concentration of Mg solid incorporation. Moreover, our Hall data indicate that the optimum thermal annealing temperature for GaN:Mg sample is ∼700℃ . For sample annealed at this temperature for 40 min, we can obtain the resistivity, hole carrier concentration and hole mobility of 0.33Ω-cm, 2×1018cm-3 and 10cm2/V.s, respectively. The corresponding Mg activation efficiency is ∼1/10 as copmared to its SIMS data. These results are among the best data ever reported for p-type Mg-doped GaN films.