Chipmakers hunt for new compound to replace silicon

Polysilicon wafers [SHUTTERSTOCK]

Chipmakers are researching new compounds to replace silicon and germanium, both widely used in manufacturing semiconductors, as new technology and devices demand better energy efficiency and performance.

Samsung Electronics is now recruiting researchers for materials that rely on electronic features like silicon, gallium and germanium.

In a recent forum, Samsung Electronics announced it would begin manufacturing gallium nitride (GaN)-based power semiconductors from 2025 for consumers, data centers and automotive applications. The company formed a task force team earlier in 2023 to study the possibility of making a business model out of compound power semiconductors.

What is a compound semiconductor?

Compound materials are used in power semiconductors to stabilize supply and distribution of electricity within electronic devices.

A single material, such as silicon and germanium, cannot withstand high electrical currents, particularly amid the competition to downsize the manufacturing process. A manufacturing process of less than 10-nanometer limits the chips' ability to contain heat.

Some of these limits can be solved by utilizing compound materials such as gallium nitride, silicon carbide and gallium oxide to make wafers.

Such compounds enable faster movement of electrons compared to silicon-based chips, resulting in more efficient energy consumption while containing heat. It can also maintain a stable function even amid high temperatures and electrical currents.

The increasing popularity of electric vehicles (EVs) will further boost demand for compound semiconductors.

A Toyota hybrid vehicle was recently equipped with a silicon carbide-based power semiconductor in its power control unit (PCU), increasing its fuel efficiency by 10 percent and downsizing the PCU size by a fifth, according to an IBK Securities report.

The Korean Industry Ministry forecasts the compound power semiconductor market to grow by an average of 7 percent annually until 2030. But Korea still lags in market share, with Europe accounting for 54 percent of the global market, followed by the U.S. with 28 percent and Japan with 13 percent.

Global race to the top

Chipmakers are jumping into the industry to get an early start.

Taiwan’s TSMC started to contract manufacture 6-inch GaN chips in 2020. Korea’s DB HiTek and SK hynix subsidiary Key Foundry are also developing 8-inch GaN chips.

Shinhan Securities forecast the GaN semiconductor industry, which was valued at $53 million in 2020, will grow to $1.1 billion by 2025. Carmakers, including Hyundai Motor, have also started rolling out studies on compound power chips for electric models.

The Korean government is also backing the boom.

The Ministries of Science and Industry promised to invest some 138.45 billion won in compound semiconductor business through 2028.

China’s recent curb on exports of gallium and germanium, along with other compound metals, will inevitably affect these industry-wide efforts but will not have a big impact.

“We are not currently mass-producing compound semiconductors, nor are we directly using them in the chip industry,” an industry source said.

Lee Kang-yoon, an electrical engineering professor at Sungkyunkwan University, suggested the “high price” was the biggest hurdle for compound semiconductors.

To overcome the current silicon-based chips' limits in containing heat and speed, we have started researching compound semiconductors,” he said.

“The development of new compounds like silicon germanium and gallium arsenic continues, but the biggest Achilles' heel is the very high processing cost. I believe demand for compound chips using silicon carbide and gallium nitride will increase in areas that need high energy efficiency, such as electric vehicles and 5G networks.”

BY KO SUK-HYUN [jin.eunsoo@joongang.co.kr]