Deep Level Defects In Semi-insulating Inp, Electrical Compensation And Electrical Properties

Deep level defects and property of semi-insulating InP (SI-InP) have been studied by using Hall effect measurement and Thermally Stimulated Current spectroscopy (TSC). Nature and formation mechanism of the defects and their influence on the electrical property of the SI-InP have been discussed. Through a comparative study on as-grown Fe-doped and annealed undoped SI-InP, we found that as-grown Fe-doped SI-InP containing high concentration of defects exhibits low mobility and poor thermal stability. In contrast, the SI- InP obtained by annealing undoped InP under iron phosphorus (IP) atmosphere has high mobility and low concentration of defects. Origin and formation mechanism of some defects have been revealed based on the experimental results. By our understanding of the defect formation mechanism, we have prepared SI-InP with low concentration of compensation defects and superior electrical performance through the control of growth condition and suppression of the defects.A detail investigation about the influence of deep level defects on the electrical compensation in the as-grown Fe-doped and annealed undoped SI-InP materials has been studied by TSC spectroscopy. The electrical property of the Fe-doped SI-InP is deteriorated due to the existence of a high concentration of deep level defects, which act as compensation and trapping centres. In contrast, the concentration of deep defects is very low in annealed undoped InP and the doping of Fe acceptor by diffusion acts as the only compensation centre to pin the Fermi level, resulting in excellent electrical performance.A consistent conclusion has been made based on the analysis and discussion of the deep defects in various SI-InP. The stoichiometry of InP annealed in phosphorus ambient tends to phosphorus rich from which a large number of defects with higher concentration are generated. This deteriorates the electrical property of the material.In contrast, the annealing of InP in iron phosphide ambient is identical to astoichiometric condition through which the quantity and the concentration of thedefects are low in the material. This presents an evident phenomenon of defectsuppression. Thus the SI-InP material prepared in this way has superior electricalproperty.