EFFECTIVE NITROGEN DOPING INTO EPITAXIALLY GROWN P-TYPE ZnSe

1.用于p型ZnSe的外延生长的有效氮物质按更有效的顺序是（1）原子氮，（2）受激和电离的氮分子和（3）受激中性氮分子。电离氮的进一步加速会产生晶体缺陷.光致发光光谱中的主要发射峰随氮掺杂量的增加而变化，主要表现为：（1）中性氮受体的激子发射，（2）导带到氮受体能级的跃迁发射，（3）浅施主到氮受体对的发射，（4）深施主到氮受体对的发射.掺氮ZnSe中的补偿施主是（1）源材料中的残余施主杂质（典型的是Se中的Cl），（2）生长气氛中的氢，（3）特别是重掺杂引入的晶体缺陷（最可能的深施主模型是Se空位和Se位N的复合体）。所有这些都需要减少。氮掺杂的ZnSe的外延层和镜面对Se/Zn供给比未掺杂的和n型ZnSe敏感得多。这一事实使得难以尝试降低上述3（3）.5中所示的深施主密度。具有可比光致发光特性的ZnSe层的电学特性取决于补偿比，通过选择适当的生长条件，应降低补偿比以获得更高的电导率。

1. The effective nitrogen species for epitaxial growth of p-type ZnSe are, in more effective order, (1) atomic nitrogen, (2) excited and ionized nitrogen molecules and (3) excited neutral nitrogen molecules. Further acceleration of ionized nitrogen can bring crystal defects.2. Dominant emission peaks in photoluminescence spectragenerally chages with increased nitrogen doping as (1) exciton emission bound to neutral nitrogen acceptor, (2) emission due to transition from conduction band to nitrogen acceptor level, (3) shallow donor to nitrogen acceptor pair emisson and (4) deepdonor to nitrogen acceptor pair emission.3. Compensating donors in nitrogen-doped ZnSe are (1) residualdonor impurities in source material (typically Cl in Se), (2) hydrogen in growth atmosphere and (3) crystal defects par-ticularly introduced by heavy doping (the most probalble model of deep donors is a complex of Se-vacancy and N in Se-site). All of them need to be reduced.4. Epitaxy and mirror surface of nitrogen-doped ZnSe is much more sensitive to Se/Zn supply ratio than undoped and n-type ZnSe. This fact makes difficult an attempt to reduce deep donor density indicated in the above 3 (3).5. Electrical properties of ZnSe layrs with comparable photoluminescent properties depend upon compensation ratio, which should be reduced for higher conductivity by selecting proper growth conditions.