Pub Date : 2001-06-06DOI: 10.1109/FREQ.2001.956189
D. Malocha, M. D. da Cunha, E. Adler, D. Puccio, K. Knapp
SAW material parameters have been extracted for LGT X-cut material at various propagation angles. The extracted parameters of velocity, coupling and TCD give good correlation to predicted results based on fundamental LGT material measurements previously reported. SAW delay lines, resonators and transversely coupled resonator (TCR) have been fabricated and the initial results from experiments are presented. The results indicate that the LGT material parameters previously reported will yield reliable predictions, although the precise temperature effects are not at the same level of refinement as in quartz. Based on device results, the current LGT material used is of a high quality and suitable for SAW device applications.
{"title":"Measurements and predictions of SAW parameters and device performance on LGT-X substrates","authors":"D. Malocha, M. D. da Cunha, E. Adler, D. Puccio, K. Knapp","doi":"10.1109/FREQ.2001.956189","DOIUrl":"https://doi.org/10.1109/FREQ.2001.956189","url":null,"abstract":"SAW material parameters have been extracted for LGT X-cut material at various propagation angles. The extracted parameters of velocity, coupling and TCD give good correlation to predicted results based on fundamental LGT material measurements previously reported. SAW delay lines, resonators and transversely coupled resonator (TCR) have been fabricated and the initial results from experiments are presented. The results indicate that the LGT material parameters previously reported will yield reliable predictions, although the precise temperature effects are not at the same level of refinement as in quartz. Based on device results, the current LGT material used is of a high quality and suitable for SAW device applications.","PeriodicalId":369101,"journal":{"name":"Proceedings of the 2001 IEEE International Frequncy Control Symposium and PDA Exhibition (Cat. No.01CH37218)","volume":"414 19","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133351798","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2001-06-06DOI: 10.1109/FREQ.2001.956200
I. Mateescu, J. Zelenka, J. Nosek, G. Johnson
This paper presents the results of the theoretical and experimental investigations on frequency-temperature characteristics of plane-parallel Y-cut langasite resonators for various mass-loading conditions. Circular Sawyer Y-cut langasite blanks with 14 mm diameter, Au electrodes with 7 mm diameter and various thicknesses were used in experiments. The resonance frequencies were measured in the temperature range from -35/spl deg/C to +100/spl deg/C. First, second and third order of the frequency-temperature coefficients were computed for the fundamental, third and fifth overtones. The electromechanical coupling factors were computed from measured fundamental and third harmonic resonance frequencies. The dependence of the turnover temperatures at the fundamental, third and fifth overtones of the thickness-shear vibrations with the orientation angle of the cut YX1/sub /spl alpha// was also calculated. The results allow to adjust a desired turnover temperature in accordance with a specific application, and reveal that the influence of the mass-loading on frequency-temperature characteristics of Y-cut langasite resonators is lower than in the case of AT-cut quartz resonators.
{"title":"Frequency-temperature characteristics of the langasite resonators","authors":"I. Mateescu, J. Zelenka, J. Nosek, G. Johnson","doi":"10.1109/FREQ.2001.956200","DOIUrl":"https://doi.org/10.1109/FREQ.2001.956200","url":null,"abstract":"This paper presents the results of the theoretical and experimental investigations on frequency-temperature characteristics of plane-parallel Y-cut langasite resonators for various mass-loading conditions. Circular Sawyer Y-cut langasite blanks with 14 mm diameter, Au electrodes with 7 mm diameter and various thicknesses were used in experiments. The resonance frequencies were measured in the temperature range from -35/spl deg/C to +100/spl deg/C. First, second and third order of the frequency-temperature coefficients were computed for the fundamental, third and fifth overtones. The electromechanical coupling factors were computed from measured fundamental and third harmonic resonance frequencies. The dependence of the turnover temperatures at the fundamental, third and fifth overtones of the thickness-shear vibrations with the orientation angle of the cut YX1/sub /spl alpha// was also calculated. The results allow to adjust a desired turnover temperature in accordance with a specific application, and reveal that the influence of the mass-loading on frequency-temperature characteristics of Y-cut langasite resonators is lower than in the case of AT-cut quartz resonators.","PeriodicalId":369101,"journal":{"name":"Proceedings of the 2001 IEEE International Frequncy Control Symposium and PDA Exhibition (Cat. No.01CH37218)","volume":"03 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127246061","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2001-06-06DOI: 10.1109/FREQ.2001.956206
M. Kurashige, Y. Usami, K. Oba, M. Hattanda
Lattice defects in synthetic quartz crystals grown from various rotated Y-cut seed plates are studied. Dislocation density, OH/sup -/ concentration (alpha value), Al and Na concentrations, and other information are discussed in this paper. The states of these lattice defects included in each grown crystal are changed by their seed orientation.
{"title":"Lattice defects properties of synthetic quartz crystals grown from various rotated Y-cut seed plates","authors":"M. Kurashige, Y. Usami, K. Oba, M. Hattanda","doi":"10.1109/FREQ.2001.956206","DOIUrl":"https://doi.org/10.1109/FREQ.2001.956206","url":null,"abstract":"Lattice defects in synthetic quartz crystals grown from various rotated Y-cut seed plates are studied. Dislocation density, OH/sup -/ concentration (alpha value), Al and Na concentrations, and other information are discussed in this paper. The states of these lattice defects included in each grown crystal are changed by their seed orientation.","PeriodicalId":369101,"journal":{"name":"Proceedings of the 2001 IEEE International Frequncy Control Symposium and PDA Exhibition (Cat. No.01CH37218)","volume":"37 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115522911","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2001-06-06DOI: 10.1109/FREQ.2001.956176
F. Vernotte
It is well known that the low frequency noises (flicker FM and random walk FM) yield convergence problems unless a low cut-off frequency is introduced, the physical meaning of which is not clear. As an example, in the case of random walk FM, the mean frequency of an oscillator does not converge if the analysis duration tends toward infinity. On the other hand, linear drifts appear if a phase sequence of random walk FM is observed over a duration smaller than the inverse of its low cut-off frequency. Moreover, the estimators which are insensitive to linear frequency drifts (i.e. the Hadamard variance) converge for lower frequency noises (f/sup -4/ FM). The moment condition explains the link between the insensitivity to drifts and the convergence for low frequency noises. This condition may be summarized by the following consideration: the divergence effect of a low frequency noise for the lowest frequencies induces a false drift with random drift coefficients; the lower the low cut-off frequency, the higher the variance of the coefficients of this drift. These variances may be known by theoretical calculations. The order of the drift is directly linked to the power law of the noise. The moment condition will be demonstrated and applied for creating new estimators (new variances) and for simulating low frequency noises with a very low cut-off frequency.
{"title":"Application of the moment condition to noise simulation and to stability analysis","authors":"F. Vernotte","doi":"10.1109/FREQ.2001.956176","DOIUrl":"https://doi.org/10.1109/FREQ.2001.956176","url":null,"abstract":"It is well known that the low frequency noises (flicker FM and random walk FM) yield convergence problems unless a low cut-off frequency is introduced, the physical meaning of which is not clear. As an example, in the case of random walk FM, the mean frequency of an oscillator does not converge if the analysis duration tends toward infinity. On the other hand, linear drifts appear if a phase sequence of random walk FM is observed over a duration smaller than the inverse of its low cut-off frequency. Moreover, the estimators which are insensitive to linear frequency drifts (i.e. the Hadamard variance) converge for lower frequency noises (f/sup -4/ FM). The moment condition explains the link between the insensitivity to drifts and the convergence for low frequency noises. This condition may be summarized by the following consideration: the divergence effect of a low frequency noise for the lowest frequencies induces a false drift with random drift coefficients; the lower the low cut-off frequency, the higher the variance of the coefficients of this drift. These variances may be known by theoretical calculations. The order of the drift is directly linked to the power law of the noise. The moment condition will be demonstrated and applied for creating new estimators (new variances) and for simulating low frequency noises with a very low cut-off frequency.","PeriodicalId":369101,"journal":{"name":"Proceedings of the 2001 IEEE International Frequncy Control Symposium and PDA Exhibition (Cat. No.01CH37218)","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114821226","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2001-06-06DOI: 10.1109/FREQ.2001.956252
J. Kusters
Specification of quartz crystal parameters for oscillator applications is an inexact science. In many cases, the measured crystal performance is determined by the vendor to meet or exceed the stated specifications. Yet, the crystal will not perform as expected in the oscillator. This is especially true in center frequency and in tuning range. During the nearly 40 years that Hewlett-Packard, now Agilent Technologies, produced quartz crystals, we devoted significant engineering resources to continually increase yield throughout the entire process. Part of that work was centered on the need to have repeatable center frequency with a tolerance of /spl plusmn/0.3 ppm and a mechanical tuning range that was always at least /spl plusmn/1 ppm for a 10 MHz, 3/sup rd/ overtone, SC-cut. Continuing oscillator development eventually led to an EFC range requirement that was always at least /spl plusmn/0.5 ppm.. Key to achieving the requirements with high yield are several factors. First, the final frequency plating is done using an S-parameter network analyzer with adequate software to measure crystal performance at its future operating points. Second is an intimate knowledge of the oscillator performance, especially at the end points of both the mechanical and electrical tuning ranges. Third is a willingness to perturb the crystal parameters to meet continuing changes in the oscillator electronics.
{"title":"Improved correlation between quartz crystal manufacturing and oscillator requirements","authors":"J. Kusters","doi":"10.1109/FREQ.2001.956252","DOIUrl":"https://doi.org/10.1109/FREQ.2001.956252","url":null,"abstract":"Specification of quartz crystal parameters for oscillator applications is an inexact science. In many cases, the measured crystal performance is determined by the vendor to meet or exceed the stated specifications. Yet, the crystal will not perform as expected in the oscillator. This is especially true in center frequency and in tuning range. During the nearly 40 years that Hewlett-Packard, now Agilent Technologies, produced quartz crystals, we devoted significant engineering resources to continually increase yield throughout the entire process. Part of that work was centered on the need to have repeatable center frequency with a tolerance of /spl plusmn/0.3 ppm and a mechanical tuning range that was always at least /spl plusmn/1 ppm for a 10 MHz, 3/sup rd/ overtone, SC-cut. Continuing oscillator development eventually led to an EFC range requirement that was always at least /spl plusmn/0.5 ppm.. Key to achieving the requirements with high yield are several factors. First, the final frequency plating is done using an S-parameter network analyzer with adequate software to measure crystal performance at its future operating points. Second is an intimate knowledge of the oscillator performance, especially at the end points of both the mechanical and electrical tuning ranges. Third is a willingness to perturb the crystal parameters to meet continuing changes in the oscillator electronics.","PeriodicalId":369101,"journal":{"name":"Proceedings of the 2001 IEEE International Frequncy Control Symposium and PDA Exhibition (Cat. No.01CH37218)","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123910125","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2001-06-06DOI: 10.1109/FREQ.2001.956349
I. Mateescu, B. Capelle, J. Détaint, L. Dumitrache
In this paper the results of electrical measurements of the mass-loading influence on AT-cut quartz resonator parameters are compared with those obtained by X-ray topography analysis of the same resonators. Based on the Ballato's transmission-line analogs of the trapped-energy resonators vibrating in thickness-shear mode, the mass-loading effect on resonator characteristics was studied and the effective mass-loading, motional inductance and quality factor of quartz resonators were computed. X-ray topography measurements were performed by transmission diffraction using the synchrotron radiation. Sawyer plan-parallel polished AT quartz resonators with 14 mm diameter, 5 MHz frequency, Au electrodes with various structures, diameters and thickness were used in experiments. The results of the X-ray topography investigations are in agreement with the previous ones obtained by electrical measurements.
{"title":"X-ray topography studies on the influence of the mass-loading effect on resonator parameters","authors":"I. Mateescu, B. Capelle, J. Détaint, L. Dumitrache","doi":"10.1109/FREQ.2001.956349","DOIUrl":"https://doi.org/10.1109/FREQ.2001.956349","url":null,"abstract":"In this paper the results of electrical measurements of the mass-loading influence on AT-cut quartz resonator parameters are compared with those obtained by X-ray topography analysis of the same resonators. Based on the Ballato's transmission-line analogs of the trapped-energy resonators vibrating in thickness-shear mode, the mass-loading effect on resonator characteristics was studied and the effective mass-loading, motional inductance and quality factor of quartz resonators were computed. X-ray topography measurements were performed by transmission diffraction using the synchrotron radiation. Sawyer plan-parallel polished AT quartz resonators with 14 mm diameter, 5 MHz frequency, Au electrodes with various structures, diameters and thickness were used in experiments. The results of the X-ray topography investigations are in agreement with the previous ones obtained by electrical measurements.","PeriodicalId":369101,"journal":{"name":"Proceedings of the 2001 IEEE International Frequncy Control Symposium and PDA Exhibition (Cat. No.01CH37218)","volume":"40 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124758533","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2001-06-06DOI: 10.1109/FREQ.2001.956270
R. Borngraeber, Jens Schroeder, R. Lucklum, P. Hauptmann
Oscillator based measurements with quartz crystal resonators are analyzed. The investigations have shown, that classical thickness monitors and also many chemical vapor sensors based on a quartz crystal microbalance (QCM) work properly even with simple oscillators. It was demonstrated, that for applications in a liquid environment more sophisticated electronics are necessary. Also a comparison between the experimental results in liquids and the theoretical predictions is hardly possible without the knowledge of the oscillator behavior. As our solution we present an automatic gain controlled oscillator with two output signals, the oscillator frequency and a signal which is representing the damping of the quartz resonator. Further on a calibration method is introduced, which allows one to calculate the series resonance frequency f/sub s/ and the series resistance R/sub s/ from these oscillator signals.
{"title":"Is an oscillator based measurement adequate in a liquid environment?","authors":"R. Borngraeber, Jens Schroeder, R. Lucklum, P. Hauptmann","doi":"10.1109/FREQ.2001.956270","DOIUrl":"https://doi.org/10.1109/FREQ.2001.956270","url":null,"abstract":"Oscillator based measurements with quartz crystal resonators are analyzed. The investigations have shown, that classical thickness monitors and also many chemical vapor sensors based on a quartz crystal microbalance (QCM) work properly even with simple oscillators. It was demonstrated, that for applications in a liquid environment more sophisticated electronics are necessary. Also a comparison between the experimental results in liquids and the theoretical predictions is hardly possible without the knowledge of the oscillator behavior. As our solution we present an automatic gain controlled oscillator with two output signals, the oscillator frequency and a signal which is representing the damping of the quartz resonator. Further on a calibration method is introduced, which allows one to calculate the series resonance frequency f/sub s/ and the series resistance R/sub s/ from these oscillator signals.","PeriodicalId":369101,"journal":{"name":"Proceedings of the 2001 IEEE International Frequncy Control Symposium and PDA Exhibition (Cat. No.01CH37218)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128536012","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2001-06-06DOI: 10.1109/FREQ.2001.956193
R. Taziev
Langasite is a new piezoelectric material for high temperature sensor applications. This material possesses higher pressure sensitivity for SAW than that in alpha-quartz crystal. There are also cuts with extremely low sensitivity to pressure, all-round force compressing and change a temperature of langasite plates. In this work a detailed analysis of sensitivity of SAW resonator on the surface of langasite plates to pressure loading, temperature change and all-round force compressing of circle plate are presented. The influence of external static forces on the SAW velocity is computed in a case of circular plates (membranes). Pressure and radial in-plane stress sensitivities of the SAW velocity at any point on the surface of thin membrane as a function of langasite crystal anisotropy are presented by sensitivity contour mapping from two independent variables: direction of the SAW propagation and cut angles of langasite substrate.
{"title":"Stress, temperature and pressure behavior of SAW on langasite plates","authors":"R. Taziev","doi":"10.1109/FREQ.2001.956193","DOIUrl":"https://doi.org/10.1109/FREQ.2001.956193","url":null,"abstract":"Langasite is a new piezoelectric material for high temperature sensor applications. This material possesses higher pressure sensitivity for SAW than that in alpha-quartz crystal. There are also cuts with extremely low sensitivity to pressure, all-round force compressing and change a temperature of langasite plates. In this work a detailed analysis of sensitivity of SAW resonator on the surface of langasite plates to pressure loading, temperature change and all-round force compressing of circle plate are presented. The influence of external static forces on the SAW velocity is computed in a case of circular plates (membranes). Pressure and radial in-plane stress sensitivities of the SAW velocity at any point on the surface of thin membrane as a function of langasite crystal anisotropy are presented by sensitivity contour mapping from two independent variables: direction of the SAW propagation and cut angles of langasite substrate.","PeriodicalId":369101,"journal":{"name":"Proceedings of the 2001 IEEE International Frequncy Control Symposium and PDA Exhibition (Cat. No.01CH37218)","volume":"194 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123317196","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2001-06-06DOI: 10.1109/FREQ.2001.956180
J. Everard, C. Broomfield
Transposed flicker noise removal is demonstrated in a 7.6 GHz microwave oscillator for offsets greater than 10 kHz. This is achieved by using a GaAs based feedforward power amplifier as the oscillation sustaining stage. 20 dB noise suppression is demonstrated at 12.5 kHz offset when the error correcting amplifier is switched on. The phase noise rolls-off at (1//spl Delta/f)/sup 2/ for offsets greater than 10 kHz and is therefore set by the thermal noise to within 0-2 dB of the theoretical minimum. Preliminary results on some low frequency detection and low frequency feedback circuits are presented.
{"title":"Flicker noise removal in microwave oscillators using GaAs based feedforward amplifiers","authors":"J. Everard, C. Broomfield","doi":"10.1109/FREQ.2001.956180","DOIUrl":"https://doi.org/10.1109/FREQ.2001.956180","url":null,"abstract":"Transposed flicker noise removal is demonstrated in a 7.6 GHz microwave oscillator for offsets greater than 10 kHz. This is achieved by using a GaAs based feedforward power amplifier as the oscillation sustaining stage. 20 dB noise suppression is demonstrated at 12.5 kHz offset when the error correcting amplifier is switched on. The phase noise rolls-off at (1//spl Delta/f)/sup 2/ for offsets greater than 10 kHz and is therefore set by the thermal noise to within 0-2 dB of the theoretical minimum. Preliminary results on some low frequency detection and low frequency feedback circuits are presented.","PeriodicalId":369101,"journal":{"name":"Proceedings of the 2001 IEEE International Frequncy Control Symposium and PDA Exhibition (Cat. No.01CH37218)","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126268201","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2001-06-06DOI: 10.1109/FREQ.2001.956255
H. Bradaczek, H. Bradaczek, H. Pianowski, A.V. Kononovich, G. Hildebrandt
A new X-ray machine has been designed which allows the automatic cutting-angle measurement at a nearly arbitrary number of inspection points along the surface of large AT-cut quartz wafers and the corresponding sorting of these wafers. The measurement is based on the /spl Omega/-Scan Method combined with a laser-reflection registration and provides additionally the amount of the XX' miscutting angle and data about the surface topography. Sorting criteria to be qualified by the user may be all these values as well as their spreads or standard deviations. The sorting part of the machine will be specified for the actual wafer dimensions. Capacity (up to a few thousand wafers) and cycle time (e.g., 1 minute per wafer) depend on the wafer size and the number of inspection points.
{"title":"A new machine for the automatic position-dependent orientation measurement of at-cut quartz wafers","authors":"H. Bradaczek, H. Bradaczek, H. Pianowski, A.V. Kononovich, G. Hildebrandt","doi":"10.1109/FREQ.2001.956255","DOIUrl":"https://doi.org/10.1109/FREQ.2001.956255","url":null,"abstract":"A new X-ray machine has been designed which allows the automatic cutting-angle measurement at a nearly arbitrary number of inspection points along the surface of large AT-cut quartz wafers and the corresponding sorting of these wafers. The measurement is based on the /spl Omega/-Scan Method combined with a laser-reflection registration and provides additionally the amount of the XX' miscutting angle and data about the surface topography. Sorting criteria to be qualified by the user may be all these values as well as their spreads or standard deviations. The sorting part of the machine will be specified for the actual wafer dimensions. Capacity (up to a few thousand wafers) and cycle time (e.g., 1 minute per wafer) depend on the wafer size and the number of inspection points.","PeriodicalId":369101,"journal":{"name":"Proceedings of the 2001 IEEE International Frequncy Control Symposium and PDA Exhibition (Cat. No.01CH37218)","volume":"35 4","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120991858","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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