APPLICATION OF THE ECR SLOT ANTENNA PLASMA SOURCE FOR ION-IMPLANTATION

The electron cyclotron resonance version of the slot antenna microwave plasma source SLAN I was used with an impulse implantation (PSII) sys tem. Silicon substrates with a diameter of 2 cm were placed at a dista nce of 21 cm downstream from the source center, and have been implante d with nitrogen ions. At this position the ion concentration measured with a double Langmuir probe is 1.3 x 10(10) ions cm(-3). The substrat e holder was biased with 30 mu s pulses of voltage from 25 to 40 kV. T ypical pulse number per implantation was 34000. The plasma source was operated with 800 W microwave power (2.45 GHz) at a pressure of 0.1 Pa , with a flow of 24 seem of pure nitrogen. The results of silicon surf ace examination are presented. Secondary ion mass spectrometry (SIMS) profiles were used to compare the dose and projected range of nitrogen , oxygen and carbon. With increasing pulse voltage not only the projec ted range but also the nitrogen dose increases. This is in agreement w ith the theoretical model. With Auger electron spectroscopy (AES), nit rogen, oxygen and carbon have been detected at the surface of the impl anted substrates. The sources of contamination are discussed. (C) 1997 Elsevier Science S.A.