Abstract: Methods for forming a Si-containing film on a substrate comprise heating the substrate to a temperature higher than S50° C., exposing the substrate to a vapor including a Si-containing film forming composition containing a Si-containing precursor having the formula: SiR1yR24-x-y(NH—SiR?3)x, wherein x=2, 3, 4; y=0, 1, 2, R1 and R2 each are independently selected from H, a halogen (Cl, Br, I), an C1-C4 alkyl, an isocyanate, a C1-C4 alkoxide, or an —NR3R4 group in which R3 and R4 each are independently selected from H, a C1-C4 alkyl, provided that if R3=H, R4>C1; each R? is independently selected from H, a halogen (Cl, Br, I), or a C1-C4 alkyl, and depositing the Si-containing precursor onto the substrate to form the Si-containing film on the substrate through an ALD process. The Si-containing precursor may be selected from SiH2(NH˜Si(CH3)3)2, SiHCI(NH—Si(CH3)3)2, SiCI2(NH˜Si(CH3)3)2, SiH(NH—Si(CH3)3)3, SiCI(NH—Si(CH3)3)3, or Si(NH—Si(CH3)3)4.