Preparation Of InAs / Si Thin Film By Hot Wall Epitaxy And Its Properties

As one of important third generation materials, HgCdSe attracted widely attentions in the field of mid and long wavelength infrared detection devices. However, there is a large lattice mismatch (about 19%) between HgCdSe and Si materials, which need to prepare buffer layers to degrade the lattice mismatch. InAs material can be used as an important alternative buffer layer, owing to its lattice constant can be fitted for the HgCdSe and Si materials. In addition, InAs can be applied to magnetic resistance and Hall devices, quantum dot laser devices, solar cells and infrared detector devices, etc, due to its wide prospects for research and applications. In this work, through exploring growth conditions and annealing cycle times, high quality InAs films were prepared on Si (211) substrate by using a hot-wall epitaxy method. The phase structure, surface morphology, electrical properties and infrared optical properties of the films were obtained by X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), Hall measurements, fourier transform infrared spectroscopy (FT-IR) and so on. The results were as follows:1. InAs films with zinc-blende structure were prepared on Si (211) substrateby hot wall epitaxy. The effects of de-hydrogen temperature, source-evaporation temperature and substrate temperature on the quality of InAs/Si (211) films were investigated. By XRD, SEM and AFM, optimal growth parameters of InAs/Si (211) films were obtained:the de-hydrogen temperature is 500 ℃, the source-evaporation temperature is 950℃, the substrate temperature is 400℃. By Hall measurement, the Hall mobility of InAs/Si (211) film arrived 104 cm2·v-1·s-1, which reached the same result of InAs film on Si prepared by molecular beam epitaxy (MBE).2. Optimal InAs/Si (211) film were processed by rapid thermal cycling annealing (TCA) technology. By the analysis of XRD, SEM, AFM and FT-IR results, the effect of the annealing times on the structure, electrical and infrared optical properties were studied, and the best annealing times was 6 cycle times. By the optimal TCA times, the best crystalline quality and smooth surface morphology of InAs/Si (211) film can be obtained. From the FT-IR test and analysis, the infrared absorption edge of the film can be fitted with the band gap of InAs material.3. During the experiment of the InAs/Si (211) films preparation, two different lattice orientations of InAs (111) and InAs (211) were observed. Through XRD, SEM, AFM and Hall measurement, InAs (111) can dislocated grown on the Si(211) substrates, which maybe due to the low surface energy of InAs(111) at low de-hydrogen temperature is more stable than the high surface energy of InAs(211). InAs(111) on Si(211) can effectively reduce the point defects and stacking faults, which is benefit to prepare high crystallization quality of InAs films.