Unlocking the Full Potential of Diamond: The Need for Diamond n-MOS

Tuesday - April 16 2024, 21:28 UTC - 7 months ago

Diamond CMOS technology, with the addition of diamond n-MOS, has the potential to greatly improve the performance, reliability, and energy efficiency of high-power electronics, integrated spintronics, and sensors operating under harsh environments. Currently, only p-channel diamond MOSFETs have been widely developed, but recent advancements have shown promise for n-type diamond MOSFETs. The deep nature of phosphorus in diamond and the use of MEMS technology can further enhance the performance of n-MOSFETs and lead to the development of monolithically integrated diamond chips.

Diamond has long been considered the ultimate material for electronics due to its remarkable properties such as high thermal conductivity, high breakdown field, and high carrier mobility. However, the full potential of diamond has yet to be unlocked as symmetrical doping control, like in traditional semiconductor silicon, is needed for complementary metal-oxide-semiconductor (CMOS) technology. This is where diamond n-MOS comes into play. In this article, we explore the importance of diamond n-MOS and its potential impact on high-power electronics, integrated spintronics, and extreme sensors operating under harsh environments.

Currently, p-channel diamond MOSFETs have been extensively developed and a routine fabrication process has been established. However, the lack of diamond n-MOSs has hindered the development of all-diamond CMOS circuits. In some cases, complementary circuits have been achieved by combining diamond p-MOSs with III-nitride n-MOSs. While this is a promising strategy, it still falls short of the ultimate goal of all-diamond CMOS, especially for applications in harsh environments with high temperatures and strong radiation.

Recent advancements have demonstrated the feasibility of n-channel diamond MOSFETs. By utilizing phosphorus-doped homoepitaxal (111) diamond epilayer, researchers have successfully grown n-type diamond with precise control over crystal quality and donor distribution. This has led to n-MOSFETs with a high mobility of 150 cm2 V−1 s−1 at 573 K, a significant improvement compared to other wide-bandgap semiconductors at high temperatures. The excellent high-temperature performance of n-type diamond MOSFETs provides a pathway for the development of diamond CMOS circuits for high-power electronics, integrated spintronics, and extreme sensors.

One of the potential applications of diamond n-MOS is in the field of spintronics, which utilizes the spin of electrons for advanced computing and sensing. N-type diamonds are able to stabilize negatively charged nitrogen-vacancy (NV−) centers, making them ideal for use in diamond CMOS-integrated NV centers. This can greatly enhance the sensitivity and functionality of diamond spin electronics, which requires precise control and integrity to scale up quantum sensing protocols.

Furthermore, the deep nature of phosphorus in diamond can also benefit the development of surface p-type conductivity with hydrogen termination. This allows for the achievement of a diamond CMOS based on a planar process on lightly doped n-type diamond. Through the use of microelectromechanical system (MEMS) technology, the band structure of n-type diamond can be further engineered, leading to improved performance of n-MOSFETs. This opens up the possibility of monolithically integrated diamond chips where electronics, spintronics, and sensors are all based on diamond.

The demand for peripheral circuitry based on diamond CMOS devices has been steadily increasing with the advancements in diamond growth technologies, power electronics, spintronics, and MEMS sensors that operate under harsh conditions of high temperatures and strong radiation. The development of diamond n-MOS will play a crucial role in achieving the ultimate goal of all-diamond CMOS for integrated circuits. With the potential to greatly improve the performance, reliability, and energy efficiency of high-power electronics, integrated spintronics, and extreme sensors, diamond n-MOS is a key piece in unlocking the full potential of diamond technology.