In气氛下晶体生长对Mg掺杂p-AlxGa1-xN激活能的影响  

Influence of Indium Doping on Acceptor Activation Energy in p-type Al_xGa_(1-x)N

作　　者：张延召[1] 秦志新[1] 桑立雯[1] 许正昱[1] 于涛[1] 杨子文[1] 沈波[1] 张国义[1] 赵岚 张向锋 成彩晶 孙维国 

机构地区：[1]北京大学物理学院；人工微结构和介观物理国家重点实验室,北京100871 [2]洛阳光电研究所,河南洛阳471009

出　　处：《发光学报》2010年第1期91-95,共5页Chinese Journal of Luminescence

基　　金：国家自然科学基金(10774001,60736033,60776041,60876041);国家重点基础研究发展计划(2006CB604908,2006CB921607);国家“973”计划(TG2007CB307004)资助项目

摘　　要：Ⅲ-Ⅴ族氮化物宽禁带半导体材料体系中,普通方法生长的p型外延层电导率一般都很低,成为了制约器件性能提高的瓶颈。在p-AlxGa1-xN材料中,Mg受主的激活能较大,并且随Al组份增加而增大。通过在p-AlxGa1-xN材料生长过程中引入三甲基铟(TMIn),发现能有效地降低AlxGa1-xN材料中受主态的激活能。为研究不同In气氛下生长的p-AlxGa1-xN材料的性质,在使用相同二茂基镁(CP2Mg)的情况下,改变TMIn流量,生长了A,B,C和D四块样品。X射线衍射(XRD)组份分析表明:在1100℃下生长AlxGa1-xN外延层时,In的引入不会影响晶体组份。利用变温霍尔(Hall)测试研究了p-AlxGa1-xN材料中受主的激活能,结果表明:In气氛下生长的外延层相比无In气氛下生长的外延层,受主激活能明显降低,电导率显著提高。采用这种方法改进深紫外发光二极管(LED)的p-AlxGa1-xN层后,LED器件性能明显提高。nfluence of Indium doping on acceptor activation energy in p-type AlxGa1-xN was presented. The p-type AlxGa1-N epilayers were grown on A1N/sapphire templates by metal organic chemical vapor deposition （MOCVD）. TMIn flow rate is varied as 0, 40, 80 and 120 sccm while keeping other growth conditions changeless. X-ray diffraction （XRD） was used to determine the crystalline quality and A1 composition in AlxGa1-xN epilayers. At room temperature, the resistivity of p-type Alo.43Gao.57N epilayer grown In doping is in order of 10^4Ω·cm, but that grown without In is above 1 × 10^6Ω· cm. Variable temperature Hall-effect measurements were employed to determine the acceptor activation energy in p-type A10.43Ga0.57N epilayers. It was seen that the acceptor activation energy decreases significantly with the introduction of In. The minimum of 259 meV is obtained at TMIn flow rate of 80 sccm. It was suggested that acceptor-donor-acceptor （A-D-A） complexes could be formed in p-type Al043 Gao57 N epilayers. The formation of A-D-A complexes would decrease the acceptor activation energy in p-type AlO43Gao 57N epilayers due to lower activation energy for A- D-A complexes. In order to verify the influence of the In-ambient on acceptor activation energy, the ultraviolet light-emitting diodes （UV-LEDs） were fabricated. It was seen that there are a lower turn-on voltage and a lower diode series resistance for the UV-LEDs fabricated with p-type AlO43 Gao.57 N grown under In-doping, compared with that without In-ambient.

关 键 词：p-AlxGa1-xN In气氛 激活能 深紫外LED 

分 类 号：O472.4[理学—半导体物理]