Newly developed GaN based MEMS resonator operates stably even at high temperature

January 15, 2021

Liwen Sang, independent scientist at International Center for Materials Nanoarchitectonics, National Institute for Materials Science (also JST PRESTO researcher) developed a MEMS resonator that stably operates even under high temperatures by regulating the strain caused by the heat from gallium nitride (GaN).

High-precision synchronization is required for the fifth generation mobile communication system (5G) with a high speed and large capacity. To that end, a high-performance frequency reference oscillator which can balance the temporal stability and temporal resolution is necessary as a timing device to generate signals on a fixed cycle. The conventional quartz resonator as the oscillator has the poor integration capability and its application is limited. Although a micro-electromechanical system (MEMS) (*1) resonator can achieve a high temporal resolution with small phase noise and superior integration capability, the silicon (Si)-based MEMS suffers from a bad stability at higher temperatures.

In the present study, a high-quality GaN epitaxial film was fabricated on a Si substrate using metal organic chemical vapor deposition (MOCVD)(*2) to fabricate the GaN resonator. The strain engineering was proposed to improve the temporal performance. The strain was achieved through utilizing the lattice mismatch and thermal mismatch between GaN and Si substrate. Therefore, GaN was directly grown on Si without any strain-removal layer. By optimizing the temperature decrease method during MOCVD growth, there was no crack observed on GaN and its crystalline quality is comparable to that obtained by the conventional method of using a superlattice strain-removal layer.

The developed GaN-based MEMS resonator was verified to operate stably even at 600K. It showed a high temporal resolution and good temporal stability with little frequency shift when the temperature was increased. This is because the internal thermal strain compensated the frequency shift and reduce the energy dissipation. Since the device is small, highly sensitive and can be integrated with CMOS technology, it is promising for the application to 5G communication, IoT timing device, on-vehicle applications, and advanced driver assistance system.
-end-
The research was supported by JST's Strategic Basic Research Program, Precursory Research for Embryonic Science and Technology(PRESTO). This result was presented at the IEEE International Electron Devices Meeting (IEDM2020) held online on December 12-18, 2020, titled "Self-Temperature-Compensated GaN MEMS Resonators through Strain Engineering up to 600 K."

(1) Micro-electro mechanical systems (MEMS)

A device where mechanical components, sensors, actuators, and electrical circuit are integrated on a substrate, such as semiconductor, glass, or organic material through microfabrication technology. For the main component, three-dimensional shape and movable structures are built through etching.

(2) Metal organic chemical vapor deposition (MOCVD)

A useful crystal growth method to build a wafer for compound semiconductors. Organometallic compounds of the Group III and Group V are simultaneously provided to the heated crystalline surface of the substrate to achieve epitaxial growth.

Japan Science and Technology Agency

Related Gallium Nitride Articles from Brightsurf:

A new method to measure optical absorption in semiconductor crystals
Tohoku University researchers have revealed more details about omnidirectional photoluminescence (ODPL) spectroscopy - a method for probing semiconducting crystals with light to detect defects and impurities.

Boron nitride nanofilms for protection from bacterial and fungal infections
NUST MISIS material scientists have presented antibacterial nano-coatings based on boron nitride, which are highly effective against microbial pathogens (up to 99.99%).

Tohoku University teaches old spectroscope new tricks
Tohoku University researchers have improved a method for probing semiconducting crystals with light to detect defects and impurities.

Standing the test of time with a perfect partner
Identifying the ideal co-catalyst can significantly extend the working lifetime of solar fuel-generating photocatalysts.

Boron nitride destroys PFAS 'forever' chemicals PFOA, GenX
Rice University chemical engineers have discovered a photocatalyst that can destroy 99% of the 'forever' chemical PFOA in laboratory tests on polluted water.

New study unveils ultrathin boron nitride films for next-generation electronics
A recent study, affiliated with South Korea's Ulsan National Institute of Science and Technology (UNIST) has unveiled a novel material that could enable major leaps in the miniaturization of electronic devices.

Study: Paper-thin gallium oxide transistor handles more than 8,000 volts
University at Buffalo electrical engineers created a gallium oxide-based transistor that can handle more than 8,000 volts.

Oriented hexagonal boron nitride foster new type of information carrier
Present computers use the presence or absence of charge (0s and 1s) to encode information, where the physical motion of charges consume energy and causes heat.

NRL researchers create electronic diodes beyond 5G performance
NRL researchers have developed a new resonant tunneling diode (RTD) with performance beyond the anticipated speed of 5G.

Spin-dependent processes in the 2D material hexagonal boron nitride
Quantum technology was once considered to be something very expensive and available only to the largest research centers.

Read More: Gallium Nitride News and Gallium Nitride Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.