The United States imposes a new export ban on China: involving four technologies including EDA, gallium oxide and diamond materials
On August 12, local time, the U.S. Department of Commerce’s Bureau of Industry and Security (BIS) disclosed a new interim final rule on export restrictions in the Federal Register, involving advanced semiconductors, turbine engines and other fields.
The ban applies to EDA/ECAD software necessary for integrated circuits with a GAAFET (Around Gate Field Effect Transistor) structure, ultra-wide bandgap semiconductor materials represented by diamond and gallium oxide, pressure gain combustion (PGC) Four technologies implemented new export controls.
GAAFET related EDA software
EDA/ECAD refers to electronic computer aided software used to design, analyze, optimize and verify the performance of integrated circuits or printed circuit boards. As early as August 3, Xinzhixun reported that "the United States will cut off the supply of EDA tools related to GAAFET technology to China". The announcement of the ban further confirms the news.
As the successor of FinFET, GAAFET is considered to be the key technology for mass production of 3nm and below semiconductor process technology. At the end of June this year, Samsung has announced the first mass production of the 3nm process based on GAAFET technology. The 3nm that TSMC is currently mass-producing is still based on FinFET technology, and it is expected to introduce GAAFET technology at 2nm.
In other words, the US ban will limit the export of EDA software to China that can be used in chip designs for advanced semiconductor processes of 3nm and below. This move will limit the breakthrough of Chinese chip designers to advanced processes of 3nm and below.
BIS is also currently soliciting public comments to determine which specific features of ECAD are particularly useful in designing GaAs FET circuits to ensure that the U.S. government can effectively enforce the regulation.
Related article "It is rumored that the United States will cut off the supply of GAA technology-related EDA tools to China"
Gallium oxide and diamond
As for the wide bandgap semiconductor materials gallium oxide (Ga2O3) and diamond (including silicon carbide SiC): gallium nitride and silicon carbide are the main materials for the production of complex microwave, millimeter wave devices or high power semiconductor devices, with the potential to create more complex devices , can withstand higher voltage or temperature.
At present, compound semiconductors represented by silicon carbide and gallium nitride have received a lot of attention, and they will play a role that traditional silicon devices cannot achieve in future high-power, high-temperature, and high-voltage applications. Especially in the automotive field, one of the three emerging application fields (automotive, 5G and the Internet of Things) in the future, there will be very broad development prospects. However, gallium oxide has a wider band gap than silicon carbide and gallium nitride, which makes this compound semiconductor unique in higher power applications.
Gallium oxide is a wide-bandgap semiconductor with a band gap of EG=4.9eV, far exceeding that of silicon carbide (about 3.4eV), gallium nitride (about 3.3eV) and silicon (1.1eV), and its electrical conductivity and luminescence characteristics are good. Therefore, it has broad application prospects in optoelectronic devices and high-power scenarios. Although, the mobility and thermal conductivity of gallium oxide are low, especially the thermal conductivity is its main short board. However, relatively speaking, these disadvantages do not have much impact on the characteristics of power devices, because the performance of power devices mainly depends on the breakdown electric field strength.
△Ga2O3 has five main crystal forms: α, β, γ, δ, and ε. Among them, the β structure is the most stable, and most of the research reports related to the crystal growth and physical properties of Ga2O3 use the β structure. The breakdown electric field strength of β-Ga2O3 is about 8MV/cm, which is more than 20 times that of Si and more than twice that of SiC and GaN.
Compared with silicon materials, gallium nitride, silicon carbide, etc., the forbidden band width of diamond semiconductor materials is as high as 5.45 eV, and the biggest advantage lies in higher carrier mobility (holes: 3800 cm2V-1s-1, electrons: 4500 cm 2V-1s-1), higher breakdown electric field (>10 MVcm-1), greater thermal conductivity (22 WK-1cm-1), its intrinsic material advantage is the highest thermal conductivity in nature It can meet the needs of high power, strong electric field and radiation resistance in the future, and is an ideal material for making power semiconductor devices. It has broad application prospects in smart grid, rail transit and other fields.
However, according to Li Chengming, a professor at the Institute of New Materials Technology at the University of Science and Technology Beijing, there is still a long way to go for diamond to achieve commercial applications. The high cost and small size of diamond materials are the main obstacles restricting the development of diamond power electronics. For example, the dislocation density of nitrogen-doped diamond single crystal flakes (6 mm × 7 mm) in CVD production can currently be as low as 400 cm-2; The dislocation density is still up to the order of nearly 107 cm-2, and the high defect density remains a challenge.
pressure gain burn
Pressure Gain Combustion (PGC) is a technology that has the potential to increase the efficiency of gas turbine engines by more than 10 percent, potentially impacting aerospace, rocket and hypersonic missile systems. PGC technology utilizes a variety of physical phenomena, including resonant pulse combustion, constant volume combustion, and knocking, to create effective pressure in the combustion chamber while consuming the same amount of combustion.
BIS is currently unable to confirm whether any of the engines in production use the technology, but there has been plenty of research pointing to potential production.
