影响InGaP／InP半导体激光器阈值电流密度若干问题的研究

Investigation of Key Points Influencing Threshold Current Density of InGaAsP/InP Semiconductor Laser Diode

本文对影响ＩｎＧａＡｓＰ／ＩｎＰ激光器阈值电流密度的晶格失配，掩埋异质结构和掺杂控制等问题进行了分析和讨论．从Ｋｕｐｈａｌ和Ａｒａｉ模型着手计算了与ＩｎＰ晶格匹配ＩｎＧａＡｓＰ的熔体组成．并从实验上进行了仔细调整．获得了激射波长为１．３μｍ．失配量≤１．４×１０－３的ＤＨ结构ＬＰＥ工艺条件．探讨了新的腐蚀工艺和二次外延工艺参数对掩埋异质结构形成的影响；提出采用二次外延过程中Ｚｎ扩散来控制限制层（３）掺杂的新方法，避免了纵向ｐ－ｎ结偏位现象的出现．获得了室温下阈值电流最低小于２５ｍＡ、在６０ｍＡ直流驱动下单面光输出功率高达１２．５ｍＷ、激射波长为１．３μｍ的ＩｎＧａＡｓＰ／ＩｎＰＤＣ－ＰＢＨ激光器．

Some key points influencing threshold current density of InGaAsP/ InP semiconductor laser diode by two-step LPE were investigated. Growth parameters for InGaAsP lattice match to (100) InP (△a/ a< 0.4 ×10-3) at 1.3μm by LPE were established by calculating on Kuphal and Aral models. followed by carefully experimental modifying. The effects of a new etching process and the 2nd epitaxial conditions on the formation of the buried heterojunction structure were explored. A novel doping prooes of the confining layer (3) through the Zn diffusion during the 2nd step LPE was put forward, and the way to obtained accurate longitudinal p-n junction postition was discussed. The good performance of 1.3μm InGaAsP/ InP DC-PBH laser diode has been achieved with smallest threshold current< 25mA and light output power up to 12.5mW at room temperature.