Characterization of particle generated during plasma-enhanced chemical vapor deposition on amorphous carbon layer using particle beam mass spectrometer

Abstract

Nanoscale particles that can affect the process yield were generated using the plasma-enhanced chemical vapor deposition (PECVD) process. A particle beam mass spectrometer is remarkably useful to understand particle behavior in a reactor. The properties of nanoscale particles obtained from the exhaust line of PECVD during amorphous carbon layer (ACL) growth under various growth conditions were investigated. The number concentration and the size of the nanoscale particles generated were quite sensitive to growth parameters such as radio frequency (RF) plasma power, C2H2, and dopant (i.e., NH3 and B2H6) gas flow rate. For an ACL growth at higher RF plasma power, the average size of the nanoscale particles decreased as the number concentration of particles increased while they are opposingly increased in particle size and decreased in concentration for a higher C2H2 flow rate. A reduction in both the average nanoscale particle size and their number concentration occurred when NH3 gas was used for nitrogen-doped ACL. By contrast, ACL growth with increasing B2H6 gas flow for boron-doped ACL exhibited a larger average nanoscale particle size and number concentration. The particle number concentration was in the range of 106–108 cm−3 with average particle sizes of 100–400 nm. According to this study, the measurement of real-time particle size distribution can help to minimize the number of generated particles and optimize the ACL deposition process.