Hydrogenation remote plasma

Another approach to deposit TiN layers at low temperatures was realized by remote plasma CVD (RPCVD) [68]. Almost conformal depositions could be achieved if hydrogen was activated by the plasma. In this particular case the nitrogen needed for the TiN formation is derived from one of the ligands, and the decomposition of this ligand leads to carbon contamination. Mass spectrometry showed only dimethylamine, ethane, methane and nitrogen as decomposition products, and the following mechanism was postulated... 

Fio. 1. Schematic diagram of a remote hydrogen plasma system. 

Additional considerations in the design and operation of a remote hydrogen plasma system include the following (1) convective heat transfer between the downstream gas and the specimen can introduce a significant difference between the heater temperature and the specimen surface temperature (this effect is generally not as severe as for direct immersion in... 

Essential to the identification of H-induced defects in silicon was the use of a remote hydrogen plasma system as described in Section 1.2. The alternative of direct immersion in a plasma introduces charged-particle bombardment and possible photochemical effects that can obscure the purely chemical consequences of hydrogen migrating into silicon. While the evidence presented below strongly argues for the existence of H-induced defects, many issues remain to be resolved. 

In addition to the generation of platelets, hydrogenation of silicon also induces electronic deep levels in the band gap. As in the case of platelet formation, these defects are considered to be unrelated to either plasma or radiation damage because they can be introduced with a remote hydrogen plasma. Comparison of depth distributions and annealing kinetics of the platelets and gap states has been used to a limited extent to probe the relationship among these manifestations of H-induced defects. 

The introduction of electronic deep levels is demonstrated in Fig. 9 with low-temperature photoluminescence spectra for n-type (P doped, 8 Cl cm) silicon before (control) and after hydrogenation (Johnson et al., 1987a). The spectrum for the control sample is dominated by luminescence peaks that arise from the well-documented annihilation of donor-bound excitons (Dean et al., 1967). After hydrogenation with a remote hydrogen plasma, the spectrum contains several new transitions with the most prominent peaks at approximately 0.95, 0.98, and 1.03 eV. These transitions identify... 

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