Title :
PECVD deposition of a-B/C on Si using a surface-ECR plasma source and o-carborane precursor gas
Author :
Geddes, J.B. ; Getty
Author_Institution :
Dept. of Nucl. Eng., Michigan Univ., Ann Arbor, MI, USA
Abstract :
Summary form only given, as follows. Vacuum wall deposition of a-B/C films has had tremendous positive impact on the performance of tokamak fusion reactors. In the present work, sublimed gas from o-carborane and helium carrier gas are used to create a plasma using the surface-ECR source. The plasma operates in a pressure range of 5 to 15 mTorr and typical flow rates are 5 sccm He plus 0.5-1 sccm o-carborane vapor. The film deposition rate is approximately 200 /spl Aring//minute. Microwave power levels range from 200-500 W at 2.45 GHz. We present data from the deposition plasma, including Langmuir probe measurements and time-of-flight (TOF) analyzer measurements of elemental and molecular ion species concentrations. Plasma electron densities on the order of n/sub e/=10/sup 11/ cm/sup -3/ and electron temperatures of T/sub e//spl ap/2 eV were measured. Using these measurements a self-consistent plasma equilibrium is being modeled. The films have been analyzed for atomic constituency using XPS. Thickness is measured by profilometry. Preliminary X-ray diffraction analysis has been performed. Films with a thickness of a few thousand /spl Aring/ are routinely obtained.
Keywords :
Langmuir probes; boron; carbon; fusion reactor materials; plasma CVD; plasma density; plasma temperature; plasma-wall interactions; silicon; surface treatment; 2.45 GHz; 200 to 500 W; 5 to 15 torr; B-C; He carrier gas; Langmuir probe measurements; Si; X-ray diffraction analysis; a-B/C; atomic constituency; deposition plasma; elemental species concentrations; film deposition rate; flow rates; microwave power levels; molecular ion species concentrations; o-carborane precursor gas; plasma electron densities; pressure range; profilometry; self-consistent plasma equilibrium; sublimed gas; surface-ECR plasma source; time-of-flight analyzer measurement; tokamak fusion reactors; vacuum wall deposition; Density measurement; Electrons; Fusion reactors; Helium; Plasma density; Plasma measurements; Plasma sources; Plasma temperature; Probes; Tokamaks;
Conference_Titel :
Plasma Science, 1995. IEEE Conference Record - Abstracts., 1995 IEEE International Conference on
Conference_Location :
Madison, WI, USA
Print_ISBN :
0-7803-2669-5
DOI :
10.1109/PLASMA.1995.531480