反应溅射法制备掺硼的a—Si：H（B）薄膜的ESR研究

ESR Study of B-doped a.Si:H(B) Thin Films prepared by Reactive-Sputtering

我们应用反应溅射法制备了掺硼的a-Si:H薄膜和a-SiB:H合金薄膜。掺硼浓度(Y_g=[B_2H_6]/([Ar]十[H_2]))由10~(-6)到10~(-2)变化。研究发现,ESR信号为g_1=2.0051和g_2=2.0096两部分的叠加,前者代表Si的悬挂键Si_3~0信号,后者是由于掺B而引起的自旋信号。随着Y_g的增大,g_2由2.0090变化到2.0096,其峰一峰宽度△H_(2??)由20.5G展宽到26.0G;而g_1值和其△H_(1??)没有明显的变化。Y_g增大,两种缺陷态密度都有所增大,但g_1信号代表的B致缺陷态密度增加较快。在重掺B(Y_g≥10~(-2))的情况下,材料的性质与上述行为截然不同。

The B-doped a-Si:H thin films and a-SiB:H alloy thin-films materials have beenprepared by reactive sputtering. The B_2H_6 doping concentrations Y_g(=[B_2H_6]/([Ar]+[H_2])) are changed from 10~(-6) to 10~(-2).The ESR spectra of the samples have beenstudied and it is found that they are composed of two parts, g_1=2.0051 and g_2=2.0096. g_1 is the Si_8~0 dangling bond signal and the spin g_2 due to the B-doping.With the increase of boron concentration Y_g g_2 varies from 2.0090 to 2.0096, andIts peak width △H_(2pp) changed from 20.5G to 26.0G, but g_1 and △H_(1pp) do notchange obviously.When Y_g increases, the density of the two kinds of defects N_(1s)and N_(2s) increases too, but the N_(2s) change faster than N_(1s). In the case of heavy B-doping(Y_g≥10~(-2)), the properties of the samples are different from that discussed above,and alloy effects appear.