scholarly journals Effect of Substrate-Thickness on Voltage Responsivity of MEMS-Based ZnO Pyroelectric Infrared Sensors

2021 ◽  
Vol 11 (19) ◽  
pp. 9074
Author(s):  
Chia-Yen Lee ◽  
Cheng-Xue Yu ◽  
Kuan-Yu Lin ◽  
Lung-Ming Fu

Pyroelectric infrared sensors incorporating suspended zinc oxide (ZnO) pyroelectric films and thermally insulated silicon substrates are fabricated using conventional MEMS-based thin-film deposition, photolithography, and etching techniques. The responsivity of the pyroelectric films is improved through annealing at a temperature of 500 °C for 4 h. The temperature variation and voltage responsivity of the fabricated sensors are evaluated numerically and experimentally for substrate thickness in the range of 1 to 500 μm. The results show that the temperature variation and voltage responsivity both increase with a reducing substrate thickness. For the lowest film thickness of 1 μm, the sensor achieves a voltage sensitivity of 3880 mV/mW at a cutoff frequency of 400 Hz. In general, the results presented in this study provide a useful source of reference for the further development of MEMS-based pyroelectric infrared sensors.

Author(s):  
E. L. Hall ◽  
A. Mogro-Campero ◽  
L. G. Turner ◽  
N. Lewis

There is great interest in the growth of thin superconducting films of YBa2Cu3Ox on silicon, since this is a necessary first step in the use of this superconductor in a variety of possible electronic applications including interconnects and hybrid semiconductor/superconductor devices. However, initial experiments in this area showed that drastic interdiffusion of Si into the superconductor occurred during annealing if the Y-Ba-Cu-O was deposited direcdy on Si or SiO2, and this interdiffusion destroyed the superconducting properties. This paper describes the results of the use of a zirconia buffer layer as a diffusion barrier in the growth of thin YBa2Cu3Ox films on Si. A more complete description of the growth and characterization of these films will be published elsewhere.Thin film deposition was carried out by sequential electron beam evaporation in vacuum onto clean or oxidized single crystal Si wafers. The first layer evaporated was 0.4 μm of zirconia.


2013 ◽  
Vol 668 ◽  
pp. 767-770
Author(s):  
Tao Zhou ◽  
Hua Wei Jiang ◽  
Yue Xiao ◽  
Ying Bang Yao ◽  
Bin Shan ◽  
...  

Atomic layer deposition (ALD) is a very attractive ultra-thin film deposition technique. With the feature size of IC industry continues going down, ALD has received more and more attentions for its accurate sub-nanometer thickness control as well as superior uniformity and conformality. The further development of ALD technology emphasizes on both process and equipment innovations. A single-wafer bottom-heated reactor is constructed successfully, and the Al2O3 is deposited with ~2% uniformity across a 4-inch wafer. Furthermore, the gas delivery system and heating devices are studied by the combination of ANSYS simulation and experiments. These parameters that influence the uniformity and conformality of deposited films have been further optimized to obtain better performance. As a result, a new reactor with showerhead gas delivery and radiation heating system is designed.


2018 ◽  
Vol 25 (1) ◽  
pp. 116-122 ◽  
Author(s):  
Michael Störmer ◽  
Frank Siewert ◽  
Christian Horstmann ◽  
Jana Buchheim ◽  
Grzegorz Gwalt

Large X-ray mirrors are required for beam transport at both present-day and future free-electron lasers (FELs) and synchrotron sources worldwide. The demand for large mirrors with lengths up to 1 m single layers consisting of light or heavy elements has increased during the last few decades. Accordingly, surface finishing technology is now able to produce large substrate lengths with micro-roughness on the sub-nanometer scale. At the Helmholtz-Zentrum Geesthacht (HZG), a 4.5 m-long sputtering facility enables us to deposit a desired single-layer material some tens of nanometers thick. For the European XFEL project, the shape error should be less than 2 nm over the whole 1 m X-ray mirror length to ensure the safe and efficient delivery of X-ray beams to the scientific instruments. The challenge is to achieve thin-film deposition on silicon substrates, benders and gratings without any change in mirror shape. Thin films of boron carbide and platinum with a thickness in the range 30–100 nm were manufactured using the HZG sputtering facility. This setup is able to cover areas of up to 1500 mm × 120 mm in one step using rectangular sputtering sources. The coatings produced were characterized using various thin-film methods. It was possible to improve the coating process to achieve a very high uniformity of the layer thickness. The movement of the substrate in front of the sputtering source has been optimized. A variation in B4C layer thickness below 1 nm (peak-to-valley) was achieved at a mean thickness of 51.8 nm over a deposition length of 1.5 m. In the case of Pt, reflectometry and micro-roughness measurements were performed. The uniformity in layer thickness was about 1 nm (peak-to-valley). The micro-roughness of the Pt layers showed no significant change in the coated state for layer thicknesses of 32 nm and 102 nm compared with the uncoated substrate state. The experimental results achieved will be discussed with regard to current restrictions and future developments.


Author(s):  
R. F. Schneidmiller ◽  
W. F. Thrower ◽  
C. Ang

Solid state materials in the form of thin films have found increasing structural and electronic applications. Among the multitude of thin film deposition techniques, the radio frequency induced plasma sputtering has gained considerable utilization in recent years through advances in equipment design and process improvement, as well as the discovery of the versatility of the process to control film properties. In our laboratory we have used the scanning electron microscope extensively in the direct and indirect characterization of sputtered films for correlation with their physical and electrical properties.Scanning electron microscopy is a powerful tool for the examination of surfaces of solids and for the failure analysis of structural components and microelectronic devices.


Author(s):  
M. Grant Norton ◽  
C. Barry Carter

Pulsed-laser ablation has been widely used to produce high-quality thin films of YBa2Cu3O7-δ on a range of substrate materials. The nonequilibrium nature of the process allows congruent deposition of oxides with complex stoichiometrics. In the high power density regime produced by the UV excimer lasers the ablated species includes a mixture of neutral atoms, molecules and ions. All these species play an important role in thin-film deposition. However, changes in the deposition parameters have been shown to affect the microstructure of thin YBa2Cu3O7-δ films. The formation of metastable configurations is possible because at the low substrate temperatures used, only shortrange rearrangement on the substrate surface can occur. The parameters associated directly with the laser ablation process, those determining the nature of the process, e g. thermal or nonthermal volatilization, have been classified as ‘primary parameters'. Other parameters may also affect the microstructure of the thin film. In this paper, the effects of these ‘secondary parameters' on the microstructure of YBa2Cu3O7-δ films will be discussed. Examples of 'secondary parameters' include the substrate temperature and the oxygen partial pressure during deposition.


Author(s):  
G. Remond ◽  
R.H. Packwood ◽  
C. Gilles ◽  
S. Chryssoulis

Merits and limitations of layered and ion implanted specimens as possible reference materials to calibrate spatially resolved analytical techniques are discussed and illustrated for the case of gold analysis in minerals by means of x-ray spectrometry with the EPMA. To overcome the random heterogeneities of minerals, thin film deposition and ion implantation may offer an original approach to the manufacture of controlled concentration/ distribution reference materials for quantification of trace elements with the same matrix as the unknown.In order to evaluate the accuracy of data obtained by EPMA we have compared measured and calculated x-ray intensities for homogeneous and heterogeneous specimens. Au Lα and Au Mα x-ray intensities were recorded at various electron beam energies, and hence at various sampling depths, for gold coated and gold implanted specimens. X-ray intensity calculations are based on the use of analytical expressions for both the depth ionization Φ (ρz) and the depth concentration C (ρz) distributions respectively.


2001 ◽  
Vol 11 (PR3) ◽  
pp. Pr3-553-Pr3-560 ◽  
Author(s):  
W. Zhuang ◽  
L. J. Charneski ◽  
D. R. Evans ◽  
S. T. Hsu ◽  
Z. Tang ◽  
...  

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