Zinc bis (trimethylsilylamide) Zn(N(SiMe3)2)2 is a volatile metal-organic compound suitable for MOCVD applications.
Bis[bis(trimethylsilyl)amido]zinc Zn[N(SiMe3)2]2 was used as
Zn precursor (with ammonia as nitrogen source) for the growth of thin films of cubic zinc nitride Zn3N2 by MOCVD. The films were deposited at 275-410
°C substrate temperatures on SiO2/Si(100) and on ZnO-coated sapphire (c-plane Al2O3), with typical growth rates 600 nm/h. Polycrystalline films were obtained at a deposition temperature of 350 °C; film morphology was influenced by the temperature and the flow rate of the reactive gas. [297]
Zinc bis (trimethylsilylamide) Zn[N{Si(CH3)3}2]2, in combination with molecular oxygen as co-reactant, was applied as precursor for atmospheric pressure CVD growth of Zn2SiO4 –containing thin films at temperature ≤550 °C. As-deposited films composed of a mixture of SiO2 and material having Zn–O–Si linkages according to IR; after annealing, crystalline Zn2SiO4 was detected by X-ray and IR [300], [4] see Suh ChemVapDep 2001
Zn[N(TMS)2]2 have been tested as precursor for the growth of crystalline ZnSe films on GaAs by OMVPE, however the films of worse quality were obtained, compaired to ZnEt2. (H2Se was used as selenium source in both cases). [298]
Bis[di(trimethylsilyl)amido]zinc (BTM) was applied as nitrogen precursor for p-doped ZnSe. Its vapor pressure and decomposition behaviour was studied under pyrolytic and photo-assisted conditions. It shows some decomposition to a more volatile species in the bubbler at room temperature and then undergoes multi-step decomposition (indicated by an initial high reading on the ultrasonic monitor (Epison) which then decreases).
Although bis-(trimethylsilyl) zinc amide was shown to be useful as source for nitrogen doping of ZnSe, its application for the MOCVD has issues in terms of vapor pressure and suboptimal decomposition kinetics (contaminants left in the film). It can be also difficult to purify for use in MOCVD and may be unstable at some MOCVD operating conditions. (See also Chapter Nitrogen) [572]
Zn[N(TMS)2]2 have been tested as precursor for the growth of crystalline ZnSe films on GaAs by OMVPE, however the films of worse quality were obtained, compaired to ZnEt2. (H2Se was used as selenium source in both cases). However, Zn[N(TMS)2]2 introduced at dopant levels (with ZnEt2 utilized as the main zinc source) allowed to incorporate nitrogen into the films resulting in the p-type conductivity. [298]
See also: Rees et al., "OMVPE Growth of ZnSe Utilizing Zinc Amides as Source Compounds: Relevance to the Production of p-Type Material" Material Research Society Symposium Proceedings, vol. 242, pp. 281-286 (1992).
Rees et al., "Synthesis, Characterization and Evaluation of Zinc-Amides as Potential Dopant Sources for ZnSe OMVPE", Material Research Society Symposium Proceedings, vol. 282, pp. 63-67 (1993).
Zinc bis (dimethyl(trimethylsilyl)silylamide) Zn{N[(C(CH3)3) (Si(CH3)3)]}2 is the first structurally characterised homoleptic zinc amide. Its solid state crystal structure was reported by Rees et al. [299]
Zn[NC(CH3)3{Si(CH3)3}]2, with O2 as oxygen source, were applied for the preparation of thin films containing Zn2SiO4 by atmospheric-Pressure MOCVD at substrate temperatures ≤550 °C. As-deposited films consisted of a mixture of SiO2 and material having Zn–O–Si bonds (according to IR data). After annealing, presence of crystalline Zn2SiO4 in the films was indicated by X-ray and IR measurements. [300]