X-ray diffraction investigation of high-temperature SAW-sensor based on LGS crystal

Sakharov, S.; Рощупкин, Д. В.; Емелин, Е. В.; Иржак, Д. В.; Бузанов, О. А.; Zabelin, A.

doi:10.1016/j.proeng.2011.12.251

Cited by 10 publications

(3 citation statements)

References 2 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For over a decade, the piezoelectric substrate La 3 Ga 5 SiO 14 (LGS) has been investigated extensively at high temperatures for application in SAW sensors in harsh environments under an air atmosphere [ 5 , 6 , 7 , 8 , 9 , 10 ]. However, recent studies have revealed chemical instability of LGS and its high sensitivity to different surrounding atmospheres.…”

Section: Introductionmentioning

confidence: 99%

Tungsten as a Chemically-Stable Electrode Material on Ga-Containing Piezoelectric Substrates Langasite and Catangasite for High-Temperature SAW Devices

et al. 2016

View full text Add to dashboard Cite

Thin films of tungsten on piezoelectric substrates La3Ga5SiO14 (LGS) and Ca3TaGa3Si2O14 (CTGS) have been investigated as a potential new electrode material for interdigital transducers for surface acoustic wave-based sensor devices operating at high temperatures up to 800 °C under vacuum conditions. Although LGS is considered to be suitable for high-temperature applications, it undergoes chemical and structural transformation upon vacuum annealing due to diffusion of gallium and oxygen. This can alter the device properties depending on the electrode nature, the annealing temperature, and the duration of the application. Our studies present evidence for the chemical stability of W on these substrates against the diffusion of Ga/O from the substrate into the film, even upon annealing up to 800 °C under vacuum conditions using Auger electron spectroscopy and energy-dispersive X-ray spectroscopy, along with local studies using transmission electron microscopy. Additionally, the use of CTGS as a more stable substrate for such applications is indicated.

show abstract

Section: Introductionmentioning

confidence: 99%

Tungsten as a Chemically-Stable Electrode Material on Ga-Containing Piezoelectric Substrates Langasite and Catangasite for High-Temperature SAW Devices

et al. 2016

View full text Add to dashboard Cite

show abstract

“…[1][2][3][4][5][6][7][8] Today, the crystals of the lanthangallium silicate family are one of the most perspective materials for acoustoelectronics due to the high perfection of the crystal structure, the absence of the phase transitions up to the melting point, relatively high (compared to piezoquartz) piezoelectric modules, and low SAW velocities, which allow us to create miniature devices. [9][10][11][12][13] Note that the number of crystal cuts has a zero temperature coefficient of frequency.…”

mentioning

confidence: 99%

X-ray diffraction on La3Ga5SiO14 crystal modulated by SAW near the K absorption edge of Ga

Рощупкин

Ortéga

Vadilonga

et al. 2020

Applied Physics Letters

View full text Add to dashboard Cite

The process of x-ray diffraction on the La 3 Ga 5 SiO 14 (LGS) crystal modulated by surface acoustic waves (SAWs) near the K absorption edge of Ga (E ¼ 10 367 eV) was studied. A redistribution of the diffracted x-ray intensity between the diffraction satellites occurs at the absorption edge due to the change in the x-ray penetration depth into the crystal and an effective change in the interaction of x-ray radiation with the near-surface crystal region modulated by SAW. The intensity distribution of the diffraction satellites starts to change smoothly immediately after the K absorption edge of Ga with a decrease in the x-ray penetration depth into the crystal.

show abstract

“…There are many materials that exhibit outstanding SAW characteristics at room temperature and were listed in Section 4.2. Langasite has been in the forefront of research for high temperature SAW materials because of its piezoelectric stability up to 1473 • C [55][56][57][58][59][60][61][62][63][64]. However, langasite exhibits large acoustic propagation losses at high temper- atures that increase with frequency, making it unsuitable for devices operating at high temperatures and high frequencies.…”

Section: Gan Based Saw Devices For High Temperature Applicationsmentioning

confidence: 99%

Group III-nitride devices and applications

Justice¹

View full text Add to dashboard Cite

The group III-nitride system of materials has had considerable commercial success in recent years in the solid state lighting (SSL) and power electronics markets. The need for high efficient general lighting applications has driven research into InGaN based blue light emitting diodes (LEDs), and demand for more efficient power electronics for telecommunications has driven research into AlGaN based high electron mobility transistors (HEMTs). However, the group III-nitrides material properties make them attractive for several other applications that have not received as much attention. This work focuses on developing group III-nitride based devices for novel applications. GaN is a robust, chemically inert, piezoelectric material, making it an ideal candidate for surface acoustic wave (SAW) devices designed for high temperature and/or harsh environment sensors. In this work, SAW devices based on GaN are developed for use in high temperature gas or chemical sensor applications. To increase device sensitivity, while maintaining a simple one-step photolithography fabrication process, devices were designed to operate at high harmonic frequencies. This allows for GHz regime operation without sub-micron fabrication. One potential market for this technology is continuous emissions monitoring of combustion gas vehicles. In addition to SAW devices, high electron mobility transistors (HEMTs) were developed. The epitaxial structure was characterized and the 2-D electron gas concentrations were simulated and compared to experimental results. Device fabrication processes were developed and are outlined. Fabricated devices were electrically measured and device performance is discussed. Above all, I would like to thank my wife, Jackie, whose patience, loving support, and commitment to our family allowed me to pursue this degree. She deserves as much, if not more credit for her willingness to leave all her family and friends behind in San Diego, move to Morgantown, WV with me, and raise our son while I attended school. I would like to thank my son, Joshua, who even at a young age, showed interest and enthusiasm in my work. His questions helped me think about this work in ways I would not have otherwise. I would like to thank my advisor, Dr. Dimitris Korakakis, for taking the chance, and giving me the opportunity to conduct this research. His time, discussions, guidance and mentoring were invaluable. Not only for progressing this work, but for helping me establish a fundamental skill set and a confidence in my abilities that will allow me to be successful in my career far beyond grad school. I would like to thank the committee members, Dr. Larry Hornak and Dr. Jeremy Dawson. Both of whom made themselves available and were always willing to help when I had questions. Specifically, Dr. Hornak's help in device design to suppress the electromagnetic feedthrough of the SAW devices and Dr. Dawson's help in optimizing the fabrication processes in the cleanroom.

show abstract

X-ray diffraction investigation of high-temperature SAW-sensor based on LGS crystal

Cited by 10 publications

References 2 publications

Tungsten as a Chemically-Stable Electrode Material on Ga-Containing Piezoelectric Substrates Langasite and Catangasite for High-Temperature SAW Devices

Tungsten as a Chemically-Stable Electrode Material on Ga-Containing Piezoelectric Substrates Langasite and Catangasite for High-Temperature SAW Devices

X-ray diffraction on La3Ga5SiO14 crystal modulated by SAW near the K absorption edge of Ga

Group III-nitride devices and applications

Contact Info

Product

Resources

About