Details

Autor(en) / Beteiligte

• Huang, Qiao
• Cui, Hushan
• Zou, Zhiwen
• Cheng, Shiran
• Zhu, Lei
• Zhang, Hao
• Xue, Chaobo
• Feng, Jiali
• Hua, Qiang
• Zhu, Xiaoqing
• Liu, Wuping
• Xu, Kaidong

Titel

A Fully Automated VPD System for Noble Metal Control During CIS Manufacturing

Ist Teil von

• 2024 Conference of Science and Technology for Integrated Circuits (CSTIC), 2024, p.1-04

Ort / Verlag

IEEE

Erscheinungsjahr

2024

Link zum Volltext

Quelle

IEEE/IET Electronic Library (IEL)

Beschreibungen/Notizen

• Metallic contamination has long been reported as a source of defects for most semiconductor devices, and its impacts on complementary metal-oxide-semiconductor (CMOS) image sensors (CISs) are especially detrimental. These contaminants could be introduced during the CIS fabrication, such as ion implantation process [1]-[2]. Wafer surface concentration of certain noble metals, including Au, Ag, and Pt, needs to be controlled to no more than 0.05 to 0.2 ppt [6]. Conventional methods of metal trace analysis involve chemically collecting these elements into a scanning solution, and analyzing the diluted scanning solution by inductively coupled plasma mass spectroscopy (ICP-MS). However, detecting the concentration of noble metals on wafer surface has been particularly challenging, due to their low solubility in scanning solutions. In this paper, the authors proposed a method to effectively collect the noble metals, especially silver and gold, with an aqua regia (AR) based scanning solution to increase the collection efficiency (CE). Combined with a vapor phase decomposition (VPD) treatment of the wafer surface, and an integrated ICP-MS analysis, our fully automated method of AR based noble metal collection is of great importance to control the noble metal contamination for CIS manufacturing.