1：Experimental Design and Method Selection:

ALD Al2O3 films were grown on an hydrogen fluoride (HF)-cleaned (100) p-type Si substrate at 150 and 300 °C in a 4 in. ALD reactor using TMA as a metal precursor. H2O or O3 with concentration of ≈190 g m?3 was used as the oxygen source. High purity nitrogen gas (

2：999%) was used as purge and carrier gas. Sample Selection and Data Sources:

HF-cleaned (100) p-type Si substrate.

3：List of Experimental Equipment and Materials:

Spectroscopic ellipsometry (SE, Nano View, MG-1000), X-ray reflectometry (XRR, D8 Advanced, Bruker), high-resolution XPS (Thermo Scientific, VG ESCALAB 220i), dynamic SIMS (ION-TOF, TOF.SIMS-5), Agilent 4980a precision LCR meter, Agilent 4156a semiconductor parameter analyzer.

4：Experimental Procedures and Operational Workflow:

TMA metal precursor pulse and purge times were

5：5 and 20 s, respectively. H2O/O3 oxygen source pulse and purge times were 1/5 and 30/20 s, respectively. Data Analysis Methods:

Film thickness was measured by SE. The physical density of the film was estimated using XRR. The chemical binding states of the films and interface with the substrate were examined via ex situ high-resolution XPS. Elemental depth profiles of the films were traced using dynamic SIMS.