Low-temperature metalorganic vapor phase epitaxial growth of ZnS using diethyldisulphide as a sulphur precursor

The atmospheric pressure metalorganic vapor phase epitaxy (MOVPE) growth of ZnS using diethyldisulphide (Et2S2) as a sulphur precursor in combination with dimethylzinc:triethylammine adduct is reported. Et2S2 is used to achieve low-temperature (<400 degrees C) growth of ZnS by pyrolytic MOVPE. The substitution of diethylsulphide (Et2S) with Et2S2 lowers the temperature of the process by almost 150 degrees C, leading to growth rates in excess of 0.5 mu m/h at around 400 degrees C. The growth study is supplemented by the H-1 and C-13 nuclear magnetic resonance analysis of the Et2S2 batch used and by the results of mass spectrometry. The latter measurements allowed us to study the fragmentation path of the Et2S2+ ion. The similar to 150 degrees C reduction of the ZnS growth temperature is explained as being due to the weaker S-C bonds occurring in the Et2S2 molecule with respect to those of Et2S; this is ascribed to the occurrence of the stronger S-S bond, which destabilizes the S-C bonds.