| AVS 62nd International Symposium & Exhibition | |
| Plasma Science and Technology | Wednesday Sessions |
| Session PS+2D+SE-WeM |
| Session: | Plasma Diagnostics, Sensors and Control II |
| Presenter: | YuiLun Wu, University of Illinois at Urbana-Champaign |
| Authors: | Y.L. Wu, University of Illinois at Urbana-Champaign P. Piotrowicz, University of Illinois at Urbana-Champaign I.A. Shehelkanov, National Nuclear Research University (MEPhI) D.N. Ruzic, University of Illinois at Urbana-Champaign |
| Correspondent: | Click to Email |
As the critical dimension of the semiconductor device continues to shrink and aspect ratio continues to rise, more diagnostics are needed to accurately predict the deposition profile of features on the wafer. Traditionally, the incident ion fluxes are considered to be perfectly normal to the wafer plane due to the electric field of the plasma sheath. However from simulation results [1] the ion flux from a magnetron discharge has a narrow angular distribution and this distribution is becoming more significant as the aspect ratio increases. In order to confirm and adjust this predicted distribution a sensor to measure angular distribution of ions in an industrial scale chamber is designed and developed. The sensor is a combined gridded energy analyzer (GEA) and a quartz crystal microbalance (QCM) [2], with a high aspect ratio collimator in place of the normal electron repeller grid for angular measurement distribution measurements. The collimator is made of 3D-printed plastic elements with 600µm nominal openings which provides 1 degree angular resolution. This combined QCM and GEA setup is capable to determine fluxes of metal ions, metal atoms and argon ions at 30kW DC magnetron nominal target power. The setup is able to tilt around 10 degrees about the wafer plane in 1 degree intervals and measure the angular distribution of the ion and neutral fluxes generated by the discharge. A time resolved triple Langmuir probe was also employed to measure the plasma parameters such as electron temperature and density and scanning in a three dimensional map.
References:
1. Stout, P. J., et al. "Comparing ionized physical vapor deposition and high power magnetron copper seed deposition." Journal of Vacuum Science & Technology B 20.6 (2002): 2421-2432.
2. Meng, Liang, et al. "Downstream plasma transport and metal ionization in a high-powered pulsed-plasma magnetron." Journal of Applied Physics 115.22 (2014): 223301.