1：Experimental Design and Method Selection:

Angle dependent critical field measurements were used to study the dimensionality of the superconducting state of InN. Samples were grown by chemical vapour deposition (CVD) and plasma-assisted molecular beam epitaxy (PA-MBE) on c-oriented sapphire, with and without a GaN buffer layer.

2：Sample Selection and Data Sources:

InN thin films with varying carrier densities and mobilities were used. The details of the growth methods and structural studies have been reported earlier.

3：List of Experimental Equipment and Materials:

A cryostat where the sample could be rotated in situ allowing the angle between the direction of the magnetic field and the c-axis to be varied continuously was used. The cryostat was a sorption pumped He-3 system, reaching base temperature ≈250 mK.

4：Experimental Procedures and Operational Workflow:

Angle dependent four-probe magnetotransport experiments were carried out. The linearity of the current voltage characteristics were carefully checked for the contacts at room temperature as well as the lowest temperature to confirm the absence of a Schottky barrier.

5：Data Analysis Methods:

The upper critical field Hc2 at a given temperature was taken to be the magnetic field at which the resistance reaches half its normal state value. The temperature dependence of critical field was determined from the graph.