RF sputtering of thin semiconductor films - using polarisation impedance and gas pressure gradient to give high deposition rate

摘要

The parent patent described the deposn. of a thin film on a substrate by decomposing a gas in the plasma, the substrate being located in a vessel between an earth and a target fed with a L.f. potential difference to create a plasma near the substrate where the gas pressure is 10-2-10-4 Torr. In this addn. the substrate has a h.f. connection to the target via a polarisation impedance and the gas is supplied through a tube in which the gas pressure os 0.2-4 Torr, the tube forming gas jets directed towards the substrate. used in the mfr. of semiconductor device, e.g. to deposite a layer of Si (possibly doped) on a Si single crystal or to deposite SiC. High deposition rates are obtd. even when depositing semiconductors having a high dopant concn. The impedance ensures r.f. polarisation to avoid charge accumulation on the substrate.