Atomic layer controlled deposition of SiO2 and Al2O3 using ABAB… binary reaction sequence chemistry

Abstract Sequential ABAB… surface chemical reactions can be employed for atomic layer controlled deposition. We have examined the binary reactions SiCl 4 +2H 2 O⋌SiO 2 +4HCl for SiO 2 deposition and 2Al(CH 3 ) 3 +3H 2 O ⋌ Al 2 O 3 + 6CH 4 for Al 2 O 3 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 self-limiting, repetitive ABAB… cycling may produce layer-by-layer controlled growth. For example, the individual “A” and “B” surface reactions for SiO 2 deposition can be described by (A) Si–OH + SiCl 4 ⋌ Si–O–SiCl 3 + HCl, (B) Si–Cl + H 2 O ⋌ Si-OH + HCl. We have studied ABAB… binary reaction sequences for SiO 2 and Al 2 O 3 deposition using laser-induced thermal desorption, temperature-programmed desorption and Auger electron spectroscopy techniques on single-crystal Si(100) surfaces. Fourier transform infrared spectroscopy techniques were also employed to examine these binary reaction schemes on high surface area SiO 2 and Al 2 O 3 samples. Controlled deposition of SiO 2 and Al 2 O 3 was demonstrated and optimized utilizing the above techniques. Under the appropriate conditions, each surface reaction was self-terminating and atomic layer controlled growth was a direct consequence of the binary reaction sequence chemistry.