As the production timeline for the next-generation High Bandwidth Memory (HBM) approaches, announced by major memory semiconductor companies, these companies are ramping up efforts to improve yield rates.
According to industry sources on March 12, major memory semiconductor companies like Samsung Electronics and SK hynix are concentrating on enhancing the precision of ultra-fine processes under their plans to mass-produce the next-generation HBM, HBM3E, within the first half of the year.
Samsung Electronics is engaging with various semiconductor equipment companies both domestically and internationally to reduce defect rates and is exploring multiple directions for process improvement with them. The use of Thermal Compression Non-Conductive Film (TC-NCF) by Samsung Electronics is crucial, where optimizing heat and pressure is key, and it’s reported that discussions with equipment manufacturers are ongoing to enhance accuracy in this step. In the face of competition from SK hynix, Samsung Electronics has focused its efforts companywide and last month unexpectedly announced “Advanced TC-NCF” technology. This technology allows for a reduction in the thickness of the essential film in the TC-NCF process, enabling an increase in the number of semiconductor layers while maintaining the height of the HBM. According to market research firm TrendForce, Samsung Electronics had a 38% market share in the HBM market last year, trailing behind SK hynix, which recorded 53%.
SK hynix is also pouring efforts into research and development to maintain leadership in the next-generation market. Unlike Samsung Electronics, SK hynix utilizes a process called Mass Reflow Molded Underfill (MR-MUF) and is focusing its research on improving the liquid material that is crucial to the process. A company official explained, “The yield rate of the MR-MUF process depends on the properties of the liquid material used between the semiconductors. Our main focus so far has been on enhancing the quality of this material.”
It is known that the HBM yield rate of SK hynix, a leader in the HBM industry, is in the 60% range. This is low compared to the yield rate of over 90% for general DRAM. Unlike other memories, HBM requires a complex additional process of drilling holes in the semiconductor and stacking multiple semiconductors vertically using Through-Silicon Via (TSV), meaning that a defect in any stage could require discarding other good chips along with the defective ones. The yield rate at each step greatly impacts overall profitability, even if it changes slightly. An industry insider said, “As the number of HBM layers is expected to increase, even a 1-2% difference can lead to a difference of hundreds of billions of won in revenue.”