Method for heating a wide bandgap substrate by providing a resistive heating element which emits radiative heat in a mid-infrared band

A method of heating a substrate in a vacuum deposition process, the method comprising:

• providing a resistive heater having a resistive heating element, wherein radiative heat emitted from the resistive heating element has a wavelength in a mid-infrared band from 5 μm to 40 μm that corresponds to a phonon absorption band of a substrate, wherein the substrate comprises a wide bandgap (WBG) semiconducting material and has an uncoated surface and a deposition surface opposite the uncoated surface;
• positioning the resistive heater and the substrate in a vacuum deposition chamber, wherein the uncoated surface of the substrate is spaced apart from and faces the resistive heater;
• operating the vacuum deposition chamber at a pressure less than or equal to 5×10−4 Torr;
• and
• generating the radiative heat from the resistive heating element, wherein the uncoated surface of the substrate is directly heated by absorbing the radiative heat.