Samsung and SK Hynix Explore Laser Debonding Technology

According to South Korean media etnews, Samsung Electronics and SK Hynix have started the process technology conversion of high bandwidth memory (HBM) wafers, with the introduction of new technologies to prevent wafer warping as the core, which is considered to be aimed at the next generation HBM. It is expected that with the process transformation, the material and equipment supply chain will also undergo changes.

It is reported that Samsung Electronics and SK Hynix are currently working with partners to develop a laser method to replace HBM with wafer exfoliation (debonding) technology.

Wafer debonding is the process of separating a thinned wafer from a temporary carrier during the manufacturing process. In the semiconductor manufacturing process, the main wafer and the carrier wafer are bonded together with adhesive and then peeled off with a blade, hence it is called mechanical debonding.

As the number of layers in HBM increases, such as 12 or 16 layers, the wafer becomes thinner, and the use of blade separation methods faces limits. When the wafer thickness is less than 30 microns, there is a concern about damaging the wafer, so the process steps of etching, polishing, wiring, etc. are increased. At the same time, new adhesives that are suitable for ultra-high temperature environments need to be used. This is also the reason why the two companies chose to use lasers instead of traditional mechanical methods.

Industry insiders familiar with the issue explained that "in order to cope with extreme process environments, stronger adhesives are needed, which cannot be separated by mechanical means. Therefore, the new technology of laser has been introduced," and stated that "this is an attempt to stably separate the main wafer and the carrier wafer.

Samsung Electronics and SK Hynix are considering using various methods such as extreme ultraviolet (EUV) laser and ultraviolet (UV) laser.
Laser debonding is believed to be introduced first into the 16 layer HBM4. HBM4 uses a system semiconductor based "base chip" at the bottom of stacked DRAM memory, requiring finer processes and thinner wafers, so laser technology is considered appropriate.

When using lasers, changes in the supply chain of related materials and equipment are inevitable. The existing mechanical methods are dominated by Tokyo Electric of Japan and S Ü SS MicroTec of Germany, which occupy the top two positions in the market. Laser technology may attract more equipment companies and is expected to engage in fierce competition.

The wafer debonding adhesive is mainly supplied by 3M in the United States, Shin Etsu Chemical in Japan, Nissan Chemical, TOK, and others. It is reported that these companies are also developing new adhesive materials that can be used for laser methods instead of existing mechanical methods.

Source: Yangtze River Delta Laser Alliance