Mass spectrometry study of the gas phase reactions in the CVD of Si and in situ-phosphorus doped Si in order to explain the different growth rates

The experiments have been carried out in a vertical impinging jet type reactor in order to have a kinetically controlled growth. Two types of heating modes were used: hot wall reactor (HWR) and cold wall reactor (CWR). The gas phase compositions have been determined by coupling the reactor to a quadrupole mass spectrometer (QMS), while the growth rates were measured versus temperature and phosphine to disilane molar ratio in order to determine the species responsible for the deposits. Disilane draws a decrease in the inhibition of the growth rate which is 4 times less than in the case of monosilane as starting product. In contrast, phosphorus incorporation, which is in the range 1,5.10 19 -8.10 20 atom cm -3 , keeps the same order of magnitude