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Seifert M, Leszczynska B, Gemming T. Study of the Long-Term High-Temperature Structural Stability of RuAl Electrodes for Microelectronic Devices. MATERIALS (BASEL, SWITZERLAND) 2024; 17:2431. [PMID: 38793497 PMCID: PMC11123010 DOI: 10.3390/ma17102431] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2024] [Revised: 05/06/2024] [Accepted: 05/15/2024] [Indexed: 05/26/2024]
Abstract
The high-temperature stability of RuAl-based electrodes for application in microelectronic devices is analyzed for long-term duration. The electrodes are prepared on Ca3TaGa3Si2O14 (CTGS) substrates using SiO2 and Al-N-O cover and barrier layers as oxidation protection. The samples are annealed at 600, 700, or 800 °C in air for 192 h. Minor degradation is observed after thermal loading at 700 °C. The annealing at 800 °C for 192 h leads to a partial oxidation of the Al in the extended contact pad and to a complete oxidation of the Al within the structured interconnect electrodes. The different degradation of the interconnect electrodes and the contact pads is caused by their different lateral dimensions. In summary, long-term high-temperature stability is demonstrated up to at least 700 °C in air. Less oxidizing atmospheres should allow the application at higher temperatures and for a significantly longer duration.
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Affiliation(s)
- Marietta Seifert
- Leibniz Institute for Solid State and Materials Research, Helmholtzstr. 20, 01069 Dresden, Germany; (B.L.); (T.G.)
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Lu X, Liu J, Han G, Si C, Zhao Y, Hou Z, Zhang Y, Ning J, Yang F. Design and Fabrication of a Novel Poly-Si Microhotplate with Heat Compensation Structure. MICROMACHINES 2022; 13:2090. [PMID: 36557388 PMCID: PMC9782555 DOI: 10.3390/mi13122090] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Revised: 11/16/2022] [Accepted: 11/25/2022] [Indexed: 06/17/2023]
Abstract
I Microhotplates are critical devices in various MEMS sensors that could provide appropriate operating temperatures. In this paper, a novel design of poly-Si membrane microhotplates with a heat compensation structure was reported. The main objective of this work was to design and fabricate the poly-Si microhotplate, and the thermal and electrical performance of the microhotplates were also investigated. The poly-Si resistive heater was deposited by LPCVD, and phosphorous doping was applied by in situ doping process to reduce the resistance of poly-Si. In order to obtain a uniform temperature distribution, a series of S-shaped compensation structures were fabricated at the edge of the resistive heater. LPCVD SiNx layers deposited on both sides of poly-Si were used as both the mechanical supporting layer and the electrical isolation layer. The Pt electrode was fabricated on the top of the microhotplate for temperature detection. The area of the heating membrane was 1 mm × 1 mm. Various parameters of the different size devices were simulated and measured, including temperature distribution, power consumption, thermal expansion and response time. The simulation and electrical-thermal measurement results were reported. For microhotplates with a heat compensation structure, the membrane temperature reached 811.7 °C when the applied voltage was 5.5 V at a heating power of 148.3 mW. A 3.8 V DC voltage was applied to measure the temperature distribution; the maximum temperature was 397.6 °C, and the area where the temperature reached 90% covered about 73.8% when the applied voltage was 3.8 V at a heating power of 70.8 mW. The heating response time was 17 ms while the microhotplate was heated to 400 °C from room temperature, and the cooling response time was 32 ms while the device was recovered to room temperature. This microhotplate has many advantages, such as uniform temperature distribution, low power consumption and fast response, which are suitable for MEMS gas sensors, humidity sensors, gas flow sensors, etc.
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Affiliation(s)
- Xiaorui Lu
- Engineering Research Center for Semiconductor Integrated Technology, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China
| | - Jiahui Liu
- Engineering Research Center for Semiconductor Integrated Technology, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China
| | - Guowei Han
- Engineering Research Center for Semiconductor Integrated Technology, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China
| | - Chaowei Si
- Engineering Research Center for Semiconductor Integrated Technology, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China
| | - Yongmei Zhao
- Engineering Research Center for Semiconductor Integrated Technology, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
- School of Electronic, Electrical and Communication Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
- State Key Laboratory of Transducer Technology, Chinese Academy of Sciences, Beijing 100083, China
| | - Zhongxuan Hou
- Engineering Research Center for Semiconductor Integrated Technology, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China
| | - Yongkang Zhang
- Engineering Research Center for Semiconductor Integrated Technology, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China
| | - Jin Ning
- Engineering Research Center for Semiconductor Integrated Technology, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
- School of Electronic, Electrical and Communication Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
- State Key Laboratory of Transducer Technology, Chinese Academy of Sciences, Beijing 100083, China
| | - Fuhua Yang
- Engineering Research Center for Semiconductor Integrated Technology, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
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Sompalli NK, Mohanty A, Mohan AM, Deivasigamani P. Visible-light harvesting innovative W 6+/Yb 3+/TiO 2 materials as a green methodology photocatalyst for the photodegradation of pharmaceutical pollutants. Photochem Photobiol Sci 2021; 20:401-420. [PMID: 33721273 DOI: 10.1007/s43630-021-00028-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Accepted: 02/16/2021] [Indexed: 01/13/2023]
Abstract
In this work, we report on the synthesis of a new-age reusable visible-light photocatalyst using a heterojunction nanocomposite of W6+/Yb3+ on a mixed-phase mesoporous network of monolithic TiO2. The structural properties of the monolithic photocatalysts are characterized using p-XRD, SEM-EDAX, TEM-SAED, XPS, PLS, UV-Vis-DRS, FT-IR, micro-Raman, TG-DTA, and N2 isotherm analysis. The electron microscopic analysis reveals a mesoporous network of ordered worm-like monolithic design, with a polycrystalline mixed-phase (anatase/rutile) TiO2 composite, as indicated by diffraction studies. The UV-Vis-DRS analysis reveals a redshift in the light absorption characteristics of the mixed-phase TiO2 monolith as a function of W6+/Yb3+ co-doping. It is observed that the use of (8.0 mol%)W6+/0.4 (mole%)Yb3+ co-doped monolithic TiO2 photocatalyst, with an energy bandgap of 2.77 eV demonstrates superior visible-light photocatalysis, which corroborates with the PLS studies in terms of voluminous e-/h+ pair formation. The practical application of the photocatalyst has been investigated through a time-dependent dissipation of enrofloxacin, a widely employed antimicrobial drug, and its degradation pathway has been monitored by LC-MS-ESI and TOC analysis. The impact of physio-chemical parameters such as solution pH, sensitizers, drug concentration, dopant/codopant stoichiometry, catalyst quantity, and light intensity has been comprehensively studied to monitor the process efficiency.
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Affiliation(s)
- Naveen Kumar Sompalli
- Department of Chemistry, School of Advanced Sciences, Vellore Institute of Technology (VIT), Vellore Campus, Tamil Nadu, 632014, India
| | - Ankita Mohanty
- Department of Chemistry, School of Advanced Sciences, Vellore Institute of Technology (VIT), Vellore Campus, Tamil Nadu, 632014, India
| | - Akhila Maheswari Mohan
- Department of Chemistry, School of Advanced Sciences, Vellore Institute of Technology (VIT), Vellore Campus, Tamil Nadu, 632014, India
| | - Prabhakaran Deivasigamani
- Department of Chemistry, School of Advanced Sciences, Vellore Institute of Technology (VIT), Vellore Campus, Tamil Nadu, 632014, India.
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Xu H, Jin H, Dong S, Song X, Chen J, Xuan W, Huang S, Shi L, Luo J. Mode Analysis of Pt/LGS Surface Acoustic Wave Devices. SENSORS (BASEL, SWITZERLAND) 2020; 20:s20247111. [PMID: 33322434 PMCID: PMC7764756 DOI: 10.3390/s20247111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/21/2020] [Revised: 12/05/2020] [Accepted: 12/09/2020] [Indexed: 06/12/2023]
Abstract
Platinum (Pt) gratings on langasite (LGS) substrates are a widely used structures in high temperature surface acoustic wave (SAW) devices. Multiple modes can be excited in Pt/LGS SAW devices owing to the heavy weight of the Pt electrode and leaky waves in the LGS substrate. In this work, we report on a detailed mode analysis of Pt/LGS SAW devices, where three commonly used LGS cuts are considered. A three-dimensional (3D) finite element method (FEM) numerical model was developed, and the simulation and experiment results were compared. The experiment and simulation results showed that there are two modes excited in the Pt/LGS SAW devices with Euler angle (0°, 138.5°, 27°) and (0°, 138.5°, 117°), which are Rayleigh-type SAW and SH-type leaky wave, respectively. Only the Rayleigh-type mode was observed in the Pt/LGS SAW devices with Euler angle (0°, 138.5°, 72°). It was found that the acoustic velocities are dependent on the wavelength, which is attributed to the change of wave penetration depth in interdigital transducers (IDTs) and the velocity dispersion can be modulated by the thickness of the Pt electrode. We also demonstrated that addition of an Al2O3 passivation layer has no effect on the wave modes, but can increase the resonant frequencies. This paper provides a better understanding of the acoustic modes of Pt/LGS SAW devices, as well as useful guidance for device design. It is believed that the Rayleigh-type SAW and SH-type leaky waves are potentially useful for dual-mode sensing applications in harsh environments, to achieve multi-parameter monitoring or temperature-compensation on a single chip.
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Affiliation(s)
- Hongsheng Xu
- Key Laboratory of Advanced Micro/Nano Electronic Devices & Smart Systems of Zhejiang, College of Information Science and Electronic Engineering, Zhejiang University, Hangzhou 310027, China; (H.X.); (S.D.); (X.S.); (S.H.); (L.S.); (J.L.)
- Hangzhou Global Scientific and Technological Innovation Center, Zhejiang University, Hangzhou 310018, China;
| | - Hao Jin
- Key Laboratory of Advanced Micro/Nano Electronic Devices & Smart Systems of Zhejiang, College of Information Science and Electronic Engineering, Zhejiang University, Hangzhou 310027, China; (H.X.); (S.D.); (X.S.); (S.H.); (L.S.); (J.L.)
- Hangzhou Global Scientific and Technological Innovation Center, Zhejiang University, Hangzhou 310018, China;
| | - Shurong Dong
- Key Laboratory of Advanced Micro/Nano Electronic Devices & Smart Systems of Zhejiang, College of Information Science and Electronic Engineering, Zhejiang University, Hangzhou 310027, China; (H.X.); (S.D.); (X.S.); (S.H.); (L.S.); (J.L.)
- Hangzhou Global Scientific and Technological Innovation Center, Zhejiang University, Hangzhou 310018, China;
| | - Xinyu Song
- Key Laboratory of Advanced Micro/Nano Electronic Devices & Smart Systems of Zhejiang, College of Information Science and Electronic Engineering, Zhejiang University, Hangzhou 310027, China; (H.X.); (S.D.); (X.S.); (S.H.); (L.S.); (J.L.)
- Hangzhou Global Scientific and Technological Innovation Center, Zhejiang University, Hangzhou 310018, China;
| | - Jinkai Chen
- Ministry of Education Key Laboratory of RF Circuits and Systems, Hangzhou Dianzi University, Hangzhou 310018, China;
| | - Weipeng Xuan
- Hangzhou Global Scientific and Technological Innovation Center, Zhejiang University, Hangzhou 310018, China;
- Ministry of Education Key Laboratory of RF Circuits and Systems, Hangzhou Dianzi University, Hangzhou 310018, China;
| | - Shuyi Huang
- Key Laboratory of Advanced Micro/Nano Electronic Devices & Smart Systems of Zhejiang, College of Information Science and Electronic Engineering, Zhejiang University, Hangzhou 310027, China; (H.X.); (S.D.); (X.S.); (S.H.); (L.S.); (J.L.)
- Hangzhou Global Scientific and Technological Innovation Center, Zhejiang University, Hangzhou 310018, China;
| | - Lin Shi
- Key Laboratory of Advanced Micro/Nano Electronic Devices & Smart Systems of Zhejiang, College of Information Science and Electronic Engineering, Zhejiang University, Hangzhou 310027, China; (H.X.); (S.D.); (X.S.); (S.H.); (L.S.); (J.L.)
- Hangzhou Global Scientific and Technological Innovation Center, Zhejiang University, Hangzhou 310018, China;
| | - Jikui Luo
- Key Laboratory of Advanced Micro/Nano Electronic Devices & Smart Systems of Zhejiang, College of Information Science and Electronic Engineering, Zhejiang University, Hangzhou 310027, China; (H.X.); (S.D.); (X.S.); (S.H.); (L.S.); (J.L.)
- Hangzhou Global Scientific and Technological Innovation Center, Zhejiang University, Hangzhou 310018, China;
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Choi KK, Kim S. Effect of Palladium Electrode Patterns on Hydrogen Response Characteristics from a Sensor Based on Ta 2O 5 Film on SiC at High Temperatures. SENSORS 2019; 19:s19245478. [PMID: 31842347 PMCID: PMC6961022 DOI: 10.3390/s19245478] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Revised: 12/09/2019] [Accepted: 12/10/2019] [Indexed: 11/16/2022]
Abstract
Our study aims to fabricate a hydrogen sensor based on thermal stability analysis of Ta2O5 film, and to determine the effect of Pd electrodes on the hydrogen sensor at high temperatures. First, in order to ensure high-temperature stability of silicon carbide (SiC)-based hydrogen sensors, the thermal stability of Ta2O5 dielectric thin film at temperatures above 900 °C was studied. The sensor structure consisted of a metal-insulator-semiconductor (MIS) and a tantalum oxide (Ta2O5) dielectric film was formed by rapid thermal oxidation (RTO). The Ta2O5 film was assessed through SEM, TEM, SIMS, and dielectric breakdown strength to observe thermal stability. Secondly, hydrogen sensors using a SiC substrate were fabricated, with the process considering thermal stability. The response characteristics for hydrogen were evaluated using three types of sensors with different Pd electrode patterns. The patterns of the Pd electrode were designed as squares or grid shapes, and were characterized by 100%, 75%, and 50% area ratios of Pd electrodes covering the Ta2O5 layer. The results showed that the sensor with a 100% area ratio of the Pd electrode had better sensitivity and linear response characteristics compared to sensors with a 50% area ratio of the Pd electrode.
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Affiliation(s)
- Kyeong-Keun Choi
- National Institute for Nanomaterials Technology (NINT), Pohang University of Science and Technology (POSTECH), Pohang 37666, Korea;
| | - Seongjeen Kim
- Department of Electronic Engineering, Kyungnam University, Changwon 51767, Korea
- Correspondence: ; Tel.: +82-010-9310-4357
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The Investigation of High-Temperature SAW Oxygen Sensor Based on ZnO Films. MATERIALS 2019; 12:ma12081235. [PMID: 30991737 PMCID: PMC6515368 DOI: 10.3390/ma12081235] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/21/2019] [Revised: 03/12/2019] [Accepted: 03/17/2019] [Indexed: 12/26/2022]
Abstract
In this paper, a wireless oxygen sensor based on a surface acoustic wave (SAW) was reported. For high-temperature applications, novel Al₂O₃/ZnO/Pt multilayered conductive film was deposited on langasite substrate as the electrodes, and ZnO film obtained by the pulse laser deposition (PLD) method was used as the sensitive film. The measurements of X-ray diffraction (XRD) and a scanning electron microscope (SEM) showed that the c-axis orientation of the ZnO grains and the surface morphology of the films were regulated by the deposition temperature. Meanwhile, the gas response of the sensor was strongly dependent on the surface morphology of the ZnO film. The experimental results showed that the oxygen gas sensor could operate at a high-temperature environment up to 850 °C with good stability for a long period. The max frequency shift of the sensors reaches 310 kHz, when exposed to 40% O₂ gas at 850 °C. The calculated standard error of the sensors in a high-temperature measurement process is within 3%. Additionally, no significant signal degradation could be observed in the long-term experimental period. The prepared SAW oxygen gas sensor has potential applications in high-temperature sensing systems.
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