Carbom free MOMBE growth by comlete cracking of the metal organic precarsores.

这项工作的目的是通过从甲基自由基和金属有机前体如TMG中去除碳来实现无碳MOMBE生长。第一次尝试是甲烷(CH_4)的完全裂解，但发现这是困难的，特别是在真空中，因为甲烷在加热器上的粘连几率太小。下一次试验是一种相反的方法：使用加热的钨(W)丝产生的原子氢从金属有机化合物中去除甲烷中的甲基自由基。这似乎是可能的，因为当少量三甲基镓(TMG)通过加热的约2000ﾟC的钨丝时，似乎被裂解成镓(Galan)和甲烷。但当TMG的量增加一个数量级时，发现W丝由于与破裂的镓发生反应而断裂。最后，证实了最好的方法是使用新的前驱体二甲胺镓(GaH_3-NH(CH_3)_2-DMAG)。碳浓度降低了约5个数量级：从10^&lt；对于DMAG在550℃下生长的薄膜，用TMG生长的薄膜的碳减少到1，2×10~(-3)cm~(-3)。DMAG在保持在-10ﾟC左右的情况下稳定了大约2个月。

The aim of this work is to achieve a carbon free MOMBE growth by removing the carbon from methyl radical the metalorganic precursors, such as TMG.The first trial was complete cracking of the methane (CH_4), but it was found that it is difficult, e13EA\ : specially in vacuum, because that the sticking probability of methane on the heater is too small. Next trial was a reverse way : removal of methyl radical from metal organic as methane using atomic hydrogen produced by a heated tungsten (W) filament13EA\ : . It seemed to be possible because TMG (Trimethy gallium) was seemed to be cracked to gallium gydride (gallan) and methane, when a small amount of TMG was passed through a heated tungsten filament of about 2000ﾟC.However, when the amount of TMG was13EA\ : increased one order of magnitude in order to grow GaAs, it was found that the W filament was broken due to a reaction with the cracked gallium.Finally, it was confirmed that the best way is to use a new precursor, dimethyl amine gallan (GaH_3-NH(CH_3)_2--DMAG), which has no direct bond between Ga and C.the carbon concentration was reduced by about 5 orders of magnitudes : from 10^<20> c13EA\ : m^<-3> for the film grown with TMG to 1,2x10^<15> cm^<-3> for the film grown by DMAG at 550C.The carbon reduction was also confirmed by photoluminescence. The DMAG was stable for about 2 months as far as it was kept at about -10ﾟC.