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Perfectly conformal deposition into deep trenches or filling of them without keyhole formation is achieved (see Figure) by atomic layer deposition (ALD). Good conformality can be obtained with other CVD processes, but the unique surface‐controlled, self‐limiting growth mechanism of ALD may give the technique significant advantages over other methods for future generation IC technology.

HfO 2 films were produced from Hf[N(CH 3 )(C 2 H 5 )] 4 and H 2 O, on borosilicate glass, indium-tin-oxide (ITO), and Si(100) substrates, in the temperature range 150±325 C, using atomic layer deposition (ALD). In the temperature range 200±250 C, the growth rate of the HfO 2 films was 0.09 nm per cycle, but increased with both increasing and decreasing temperatures. The self-limiting adsorption of Hf[N(CH 3 )(C 2 H 5 )] 4 at 250 C was verified. The films were stoichiometric dioxides with an O/Hf ratio of 2.0 ± 0.1. The concentrations of residual carbon, nitrogen, and hydrogen, determined using ion beam analysis, were 0.3±0.6 at.-%, 0.1±0.2 at.-%, and 2±3 at.-%, respectively. The films crystallized at growth temperatures exceeding 150±175 C, and consisted mainly of the monoclinic HfO 2 phase. The refractive index of the films varied between 2.08 and 2.10. The effective permittivities of the HfO 2 films grown in the temperature range 200±300 C varied between 11 and 14.

TaN, Ta 3 N 5 , and TaO x N y films were deposited by the atomic layer deposition technique.The alternate surface reactions between TaCl 5 and NH 3 resulted in Ta 3 N 5 films, but when elemental zinc, serving as an additional reducing agent, was supplied on the substrates between the TaCl 5 and NH 3 pulses, TaN with a resistivity of 9 × 10 -4 Ω cm was obtained. TaO x N y films were grown by depositing first thin Ta 3 N 5 layers which were then partially oxidized by single water pulses. By varying the number of the Ta 3 N 5 deposition cycles between the water pulses, the oxygen-to-nitrogen ratio of the films was controlled. The permittivity of the TaO x N y films was around 30 which is somewhat higher than that of Ta 2 O 5 .