本論文採用由圓形傳輸線理論( CTLM )，透過微影技術將CTLM光罩圖形轉印到磷氮化銦鎵磊晶層，然後將不同金屬鍍在磷氮化銦鎵磊晶層做成電極，測得I-V特性曲線，根據圓形傳輸線理論公式，求得接觸電極的特徵電阻。發現以銦鋁合金當磷氮化銦鎵電極，不需經由熱退火，即可趨於歐姆接觸特性，而以鎳金屬當電極需經由熱退火至600℃，才慢慢趨近於歐姆接觸特性。
呈現更好的蕭特基整流特性。但試片經由退火之後，由試片的I-V曲線得知，試片會和原本退火前隨著氮含量提高，而蕭特基整流特性跟著變好的趨勢相反，經退火後試片之I-V曲線會因為氮含量提高而呈現較差的歐姆接觸特性。 This thesis focuses on the contact characteristics of InGaPN/GaAs. InGaPN can be adjusted to be lattice-matched to GaAs substrate by introducing a very small amount of nitrogen, and the conduction-band discontinuity between InGaPN and GaAs will decrease significantly. It will greatly improve the device characteristics of heterojunction bipolar transistors. InGaPN epilayers were grown on GaAs substrate by MOCVD. They were examined by X-ray and photoluminescence system. It is found that for a high nitrogen composition InGaPN layer, the flow rates of group Ⅲ compound must be high enough to react thoroughly with the group Ⅴ DMHy and TBP, so that a good quality of InGaPN layer can be obtained.
This thesis adopt the circular transmitting line theory. The CTLM mask pattern was transferred to InGaPN epilayers by lithography. After that, electrodes were formed by depositing different metal on InGaPN epilayers. Then we measured the I-V curve, and employed the CTLM formula to obtain the specific contact resistance. We discovered that if the electrode material is indium aluminum alloy, it does not require annealing to be ohmic. When the electrode is nickel metal, it must be annealed to 600℃, so that the contact becomes ohmic.
Experimentally, it is found that increasing the amount of nitrogen in InGaPN epilayer will improve the epitaxial quality and luminescence characteristics. The metal/semiconductor contact current will also increase and has a better Schottky rectifying properties. But after annealing, the samples follow different trend, the ohmic contact characteristics become poorer when the amount of nitrogen is increased.