Study Of High Quality Large Diameter Indium Phosphide Single Crystal

Indium Phosphide is a kind of important semiconductor material. InP is being used as a platform for a wide variety of fiber communications components, including lasers, LEDs, Semiconductor optical amplifiers, modulators and photo-detectors. Semi-Insulating InP is used in microelectronics devices and integrated opto-electronic circuits. This paper used a direct P-injection synthesis and LEC crystal growth method to prepare polycrystalline InP and to grow high quality, large diameter InP single crystal in a puller. Crystalline perfection of our four-inch InP was studied by EPD measurement of (100) wafers. The measured average EPD of four-inch S-doped substrates could be reduced to less than 5(104cm-2. The carrier concentration of the S-doped InP is 3.6(1018cm-3. Twin-free <100>InP single crystals with 4 inch diameters have been grown reproducibly through the optimization of thermal field. The thermal field was studied by an analysis of the heat transfer and a few key factors influencing the temperature fluctuation of the melt in the liquid encapsulated Czochraski (LEC) process. The solid-liquid interface of InP crystal is kept flat as revealed by observation of impurity striation. InP wafer with good electrical uniformity and low dislocation density can be obtained. Controlled the angle of the early stage 70(-180( will avoid the twin of the large diameter of InP crystal. High purity InP is necessary for the preparation of high quality InP single crystal especially low Fe content semi-insulating and annealed undoped semi-insulating InP single crystal. We can get InP ingots with very low concentration silicon by using this method. In the InP crystal the main impurity is silicon, which acts as a shallow donor in the crystal. This kind of InP can be made semi-insulating with high temperature annealing or low iron doping level. This paper presents a model to explain the possible mechanisms of the Semi-Insulating behavior of bulk InP material. The physical properties of SI-InP have been studied by Positron.