Phase change material radio-frequency switch for low power consumption and methods for forming the same

A method of forming a device structure comprising:

• forming a heater line over a substrate;
• depositing an inhomogeneous aluminum nitride layer over the heater line as a vertical stack of component aluminum nitride layers;
• and
• forming a phase change material (PCM) line over the inhomogeneous aluminum nitride layer, wherein the PCM line comprises a middle portion that overlies the heater line, a first end portion adjoined to a first side of the middle portion, and a second end portion adjoined to a second side of the middle portion.

A method of forming a device structure comprising:

• depositing a heater material layer over a substrate;
• depositing a continuous inhomogeneous aluminum nitride layer on a top surface of the heater material layer by performing a reactive sputtering process using an aluminum-containing sputtering target and reactive nitrogen-containing molecules;
• patterning the heater material layer and the continuous inhomogeneous aluminum nitride layer to form a heater line and a patterned aluminum nitride layer, respectively;
• and
• forming a phase change material (PCM) line over the patterned aluminum nitride layer.