Research On Synthesis And Properties Of Doped Nanocrystalline Silicon Thin Films By PECVD

This paper, the nanocrystalline silicon thin films prepared by PECVD, the experiment using 10% SiH4 as silicon source, on ordinary glass substrate boron doped silicon thin films were deposited. Preparation process parameter range is as follows, deposition temperature:350℃-550℃; SiH4 gas flow:10 to 50 SCCM; Rf power:60-140 W; background vacuum degree:7.5 x 10₄ pa; deposition pressure:100 pa; The deposition time:30 to 60 min. Influence of deposition temperature, RF power and other parameters on silicon thin films structure and electrical properties were studied by means of scanning electron microscopy （SEM）, X-ray diffraction （XRD） and four probe Four-Probe etc. The results showed that when preparing the B doped silicon thin films by PECVD, with the increase of substrate temperature, the resistance was decreased and then increased, and the temperature range of 450℃-500℃ was favorable for the incorporation of silicon thin films. The electrical resistance decreases and then increases, when doped with boron, with the increase of the RF power. When the RF power was 100 W compared with 60W, the electrical resistance decreased by an order of magnitude. Therefore, the RF power is higher than 60 W, it is helpful for the B element to be incorporated into the silicon thin films.Using electrochemical workstation CS350 measured the corrosion process of silicon thin films, studied the influence of silicon thin-film preparation parameters such as substrate temperature and RF power on its corrosion rate, and observed the effect of hydrofluoric acid concentration on silicon thin-films surface morphology after corrosion. The results show that, when the substrate temperature is 500℃ and RF power is 100 w, prepared silicon thin films was corroded faster, with poor corrosion resistance.