Evaluation of Hindrance to the Growth of SiN Passivation Layer by Contamination of Fluoride Ions in Front Opening Unified Pod (FOUP)

Gil Joo Song; Sung Min Hwang; Soo Jong Koo; Hyoung Ryeun Kim; Hee Chang Jang; Jeong Hoon Hong; Hyun Yul Park; Euiji Choi; Jin Young Kim; Tae Yong Noh; Eungsun Lee; Seoung-Kyo Yoo

doi:10.4209/aaqr.2014.10.0238

Evaluation of Hindrance to the Growth of SiN Passivation Layer by Contamination of Fluoride Ions in Front Opening Unified Pod (FOUP)

Gil Joo Song¹, Sung Min Hwang¹, Soo Jong Koo¹, Hyoung Ryeun Kim¹, Hee Chang Jang¹, Jeong Hoon Hong¹, Hyun Yul Park¹, Euiji Choi²^,3, Jin Young Kim², Tae Yong Noh⁴, Eungsun Lee⁴, Seoung-Kyo Yoo ⁴

+ Show author affiliations

¹Contamination Quality Engineering, Manufacturing and Technology Division, SK Hynix Semiconductor Inc., 2091 Gyeongchung-daero Bubal-eub, Icheon-si, Gyeonggi-do, Korea
²Fuel Cell Research Center, Korea Institute of Science and Technology, Hwarangno 14-gil 5, Seongbuk -gu, Seoul 136-791, Korea
³Applied Chemistry, Department of Materials Science and Engineering, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka, 819-0395, Japan
⁴WITHTECH INC. CO., LTD., 300 Techno 2Rd, Yuseong-gu, Daejeon 305-510, Korea

Received: October 7, 2014
Revised: December 30, 2014
Accepted: May 15, 2015
Download Citation: ||https://doi.org/10.4209/aaqr.2014.10.0238

Download: PDF

Cite this article:
Song, G.J., Hwang, S.M., Koo, S.J., Kim, H.R., Jang, H.C., Hong, J.H., Park, H.Y., Choi, E., Kim, J.Y., Noh, T.Y., Lee, E. and Yoo, S.K. (2015). Evaluation of Hindrance to the Growth of SiN Passivation Layer by Contamination of Fluoride Ions in Front Opening Unified Pod (FOUP). Aerosol Air Qual. Res. 15: 2175-2183. https://doi.org/10.4209/aaqr.2014.10.0238

HIGHLIGHTS

The inside of FOUP can be contaminated by airborne molecules in cleanrooms.
Thickness of SiN layer on a wafer was decreased by contaminated FOUP.
Maximum of 12% of the SiN layer was eroded by exposure to residual fluoride ions.
There was no thickness degradation of deposited SiN layer by pre-cleaned FOUP.
Cleaning and monitoring the inside of FOUPs are necessary after an etching process.

ABSTRACT

We have investigated the hindrance to the deposition growth of silicon nitride (SiN) passivation layer from the contamination by airborne molecules in the front opening unified pod (FOUP). In particular, an artificial contamination of FOUP by fluoride ions as the source of the contaminants is utilized to elucidate the influence of contamination on the wafer surface. When the bare wafer surface is exposed to fluoride ions in the contaminated FOUP, the deposited thickness of the SiN layer is observed to decrease to a maximum of 11 Å from our experimental condition. On the other hand, there is no appreciable variation in the thickness of deposited SiN layer stored in the pre-cleaned FOUP. Based on the analytical results of wafer surfaces and FOUPs, we believe that the contamination of fluoride ions on wafer surfaces is originated from the contaminated surface of FOUP. Therefore, we conclude that it is necessary to clean and monitor the inside of FOUP on a regular basis, especially after wet or dry etching processes, which generates gaseous impurities.

Keywords: Airborne molecular contaminants (AMC); Cleanroom contamination; Front opening unified pod (FOUP); Fluoride ion; SiN layer