CHEMICAL-VAPOR-DEPOSITION IN HIGH-DENSITY LOW-PRESSURE PLASMAS - REACTOR SCALE-UP AND PERFORMANCE

In most applications, plasma enhanced chemical vapor deposition (CVD) of high-quality materials requires control of process parameters over a wide range. In particular, high-density low-pressure plasmas capable of producing significant ion fluxes compared to neutral fluxes, and i ndependent substrate biasing which allows accurate adjustment of the i on bombardment energy may lead to high-performance deposited layers. R esults in low-temperature Si epitaxy, SiO2, CU and W deposition are pr esented which illustrate the capabilities of such plasmas. However, de position rate and film uniformity remain the key requirements in many industrial fields, including the microelectronics industry with the pr ocessing of flat panels and increase in wafer diameters. In fact, the limiting factor of many industrial applications lies in the difficulty of producing large (up to square meters) uniform, dense plasmas. In t he conventional cylindrical configuration of plasma reactors, the abil ity to process large-dimension substrates is dependent on the generati on of large volumes of plasma. Unfortunately, due to ion volume recomb ination, the production of large volumes of uniform dense plasma must be ruled out. Clearly, treatment of a planar substrate with a uniform plasma source is more suitable. The uniform distributed electron cyclo tron resonance (UDECR), in which linear microwave applicators can sust ain constant amplitude standing waves along a multipolar magnetic stru cture, can be used to make large planar plasma sources. The performanc e of such a plasma is presented in terms of uniformity and density, al lowing the process optimized in laboratory reactors to be scaled-up to much larger reactors without any alteration in the characteristics.