ION-IMPLANTATION BASED ON THE UNIFORM DISTRIBUTED PLASMA

For over a decade, our group has been working on the development of di stributed electron cyclotron resonance (DECR) plasma sources. The unif orm distributed plasma (UDP) is the latest outgrowth of DECR, which ha s proved to be a flexible concept, leading to task-adapted plasma sour ces. Our plasma-based ion implantation (PBII) reactor is a 60 cm diame ter, 70 cm high cylinder. The inside of the cylinder wall is covered w ith an array of 24 tubular magnets, 2.45 GHz microwave power feeds, an d wave propagators. This peripheral plasma source of a good square met er produces a uniform distributed plasma (UDP), suitable for the treat ment of wafers, pipes or object of arbitrary form. Initial PBII plans concern the nitridation of silicon wafers. At 1 mTorr pressure and 1.3 kW input power, the N-2 plasma has a density of 2 x 10(10) ions cm(-3 ) and an electron temperature of 1.2 eV. The N+/N-2(+) ratio of 7/3 in the N-2 UDP plasma, determined by quadrupole mass spectrometry, is fa vorable for PBII applications. A 45 kV pulsed power supply is availabl e for initial tests, but should be supplanted by a more powerful sourc e for meaningful experiments. (C) 1997 Elsevier Science S.A.