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[Session 3: Reliability] An Effective Approach to Monitor Potential Reliability Failure in the Advanced Devices

오후 3:30 - 오후 4:00

As semiconductor devices scale down in size, the sensitivity of reliability to process variation increases. This is due to the high reliability requirements for advanced system applications, the narrowing process margins induced by scaled pitches and the high sensitivity of devices to material elements. In order to mitigate these challenges for advanced devices, reliability improvements are required at the circuit and process levels.

In search of reliability improvements at the circuit level, circuit designers continue to optimize error correction code (ECC), redundancy and bias temperature instability (BTI). At the process level, however, specific materials or process chambers can degrade reliability of the devices in program disturb, induced by additional charge traps in the adjacent cells and poor data retention due to contamination by killer elements and complex structures, although they may be required from a process integration perspective.

It is difficult to effectively detect killer elements during the process, which can create or accelerate reliability failure. Several killer elements are known to cause reliability degradation: F (fluorine), Cl (Chlorine), local strains in the SiGe layers and plasma-induced traps at the gate oxide interfaces. It is also understood that cosmic rays from the universe can accelerate reliability failures. However, device reliability is complex; only a few failure mechanisms are well understood.

We find that an effective approach to prevent reliability failure is to detect potential killer elements in the process, maintain them under threshold levels and screen out heavily contaminated wafers before wafer fabout. In this paper, we address the relationship between specific killer elements and reliability and review the enablers of in-line metrology that can prevent reliability failure by early detection and monitoring of variation of killer elements in fabs.

Speaker

Han Sang Hyun

Sang Hyun Han

Vice President of Strategic Marketing, NOVA
  • Earned Ph.D. from Iowa State University, Ames, Iowa, USA in 1992
  • Worked at US Department of Energy until 1995
  • Worked several semiconductor chip makers for device and process integration, thin film, diffusion, yield engineering) until 2008
    • Hyndai Electronics (Current SK hynix), Chartered (current Global Foundries), tsmc & Philps fabs, SMIC
  • Served for KLA as several different roles (Corporate marketing, Technical director, Product strategic marketing) from 2008 October until 2019 early April
  • Joined Nova Measuring Instruments as VP of Strategic marketing in 2019 April