Study on the growth and characterization of InAsSbP homojunction diodes by liquid phase epitaxy

• Main Authors: Chia-Te Lin, 林家德
• Other Authors: Wu-Yih Uen
• Format: Others
• Language: en_US
• Published: 1999
• Online Access: http://ndltd.ncl.edu.tw/handle/38616407733970516441

碩士 === 中原大學 === 電子工程學系 === 87 === Abstract InAsSbP quaternary alloys lattice-matched to InAs substrate are promising materials for 2-4um wavelength optical sources. By using a supercooling technique of LPE, quaternary alloys of InAsSbP are successfully grown on the (100) InAs substrate. It is indicated that the amounts of supercooling temperatureΔT adopted have dramatic effects on both the carrier concentration and the surface morphology of the grown epilayer. A quaternary InAsSbP (x~0.094, y~0.06) layer with mirror-like surface and flat interface can be obtained by the use of supercooling temperature ΔT=10℃. A low background concentration of 5x1016cm-3 from the Hall measurements is achieved for these quaternary epilayers. The lattice-mismatch between the epilayer and the substrate is estimated as only -0.038% by x-ray diffraction. The InAsSbP diodes are successfully fabricated and their electrical properties are measured. It is found that the dark current is dominated by different mechanisms as the temperature range varies. When T>180K, the dark current is dominated by the diffusion mechanism; when T in the range between 140K and 180K, the generation-recombination mechanism comes to dominate; and when T<140K, the tunneling mechanism dominates the dark current. The temperature dependence of RoA product of the InAsSbP diodes is measured. The value of RoA is about 2.9x106Ω-cm2 when the temperature reaches 80K and it degrades to 6555Ω-cm2 when the temperature is raised to higher than 220K. From the I-V characteristics, it demonstrates a forward bias turn-on voltage of 0.06V with an ideality factor of 1.1 at 300K. The breakdown voltage of the diodes is about -2.3V. From the room temperature C-V characteristics, the junction capacitance of diode is 315.2pF and the potential voltage is estimated to be about 0.28V.