Radio frequency switch for multi-band filter applications and methods for forming the same

A switch structure comprising:

• a first electrode;
• a second electrode;
• a first heater line;
• a second heater line;
• and
• a first phase-change material (PCM) line electrically connecting the first electrode and the second electrode, wherein:
• the first PCM line has a channel length in a first horizontal direction equal to a distance between proximate sidewalls of the first electrode and the second electrode;
• the first PCM line is formed over the first heater line and wherein a first overlap area between the first heater line and the first PCM line in a plan view is a first PCM cell;
• the first PCM line is formed over the first second line and wherein a second overlap area between the second heater line and the first PCM line in the plan view is a second PCM cell, and
• wherein a resistance of the first PCM line is a function of the channel length, the first PCM cell, and the second PCM cell.

A method of forming a semiconductor structure, the method comprising:

• forming a dielectric isolation layer having a planar top surface over a substrate;
• forming at least two heater lines over the planar top surface;
• forming at least one heater-capping dielectric plate over the at least two heater lines;
• forming a phase-change material (PCM) line over the at least one heater-capping dielectric plate,
• forming a first electrode and a second electrode, wherein a first end portion of the PCM line contacts the first electrode and a second end portion of the PCM line contacts the second electrode;
• and
• forming a PCM-capping dielectric plate over the PCM line.