ATOMIC LAYER CONTROLLED DEPOSITION OF SIO2 AND AL2O3 USING ABAB - BINARY REACTION SEQUENCE CHEMISTRY

Sequential ABAB... surface chemical reactions can be employed for atom ic layer controlled deposition. We have examined the binary reactions SiCl4 + 2 H2O --> SiO2 + 4 HCl for SiO2 deposition and 2 Al(CH3)3 + 3 H2O --> Al2O3 + 6 CH4 for Al2O3 deposition. Each binary reaction (A B --> products) was performed sequentially by individual exposures to the A reactant and then the B reactant. If each surface reaction is se lf-limiting, repetitive ABAB... cycling may produce layer-by-layer con trolled growth. For example, the individual ''A'' and ''B'' surface re actions for SiO2 deposition can be described by (A) Si-OH + SiCl4 --> Si-O-SiCl3 + HCl, (B) Si-Cl + H2O --> Si-OH + HCl. We have studied ABA B... binary reaction sequences for SiO2 and Al2O3 deposition using las er-induced thermal desorption, temperature-programmed desorption and A uger electron spectroscopy techniques on single-crystal Si(100) surfac es. Fourier transform infrared spectroscopy techniques were also emplo yed to examine these binary reaction schemes on high surface area SiO2 and Al2O3 samples. Controlled deposition of SiO2 and Al2O3 was demons trated and optimized utilizing the above techniques. Under the appropr iate conditions, each surface reaction was self-terminating and atomic layer controlled growth was a direct consequence of the binary reacti on sequence chemistry.