Inductively Coupled Discharge Plasma Accelerator

Summary form only given. Electromagnetic acceleration for generating an electrically neutral, high flux plasma beam and a system for carrying out this method are studied for the semiconductor etching process having no charging damage and space missions. In the capacitively coupled discharge plasma accelerator, a certain amount of electrode sputtering is inevitable from the ion bombardment flux. This causes serious problems in semiconductor etching process and usual plasma thrusters. Our system consists of the inductively coupled discharge plasma accelerator, stainless steel vacuum chamber with turbomolecular pumping, and power supply system. The accelerator consists of two coaxial cylinders made of dielectric material such as quartz. The induction coils are installed at the surface of external and internal cylinders for the designed magnetic field configuration directed radially and having axial gradient. Plasma in an inductive discharge is created by application of 2 MHz RF power to a non-resonant inductive coil. Interaction of discharge current with the magnetic field provides a (JtimesB) body force to accelerate the plasma away from the accelerator. Our experimental results show the another way of plasma thrusters, and the plasma accelerator can be utilized in semiconductor process. The plasma flux to the wafer is electrically neutral, the plasma density is more than 10¹¹/cm^-3, and the ion kinetic energy is expected to be 50 eV for the consumed power about 2000 W