Pub Date : 1991-01-30DOI: 10.1109/MEMSYS.1991.114776
O. Tabata, K. Shimaoka, S. Sugiyama
Details of the etching of polysilicon sacrificial layers using a KOH etching solution have been studied. Etching rates showed strong dependence on KOH concentration and the structure pattern of the layers. For the clarification of the etching process, in situ observation of an etching process for various micro-membrane structures with polysilicon sacrificial layers has been done. Etching observation equipment was created for this purpose. The equipment is capable of monitoring and recording the etching process in situ under various etching conditions such as temperatures, flow rates and concentrations. It is shown from in situ observation that hydrogen bubbles play an important role in supplying fresh etching solution to the surface to be etched away. Repeated accumulation and exhaust of hydrogen bubbles cause strong oscillatory movement of the membrane structures. This movement results in the fracture of the membrane due to the increase in membrane stress. Based on these results, a system for in situ observation and stress analysis of a wet etching process is proposed.<>
{"title":"In situ observation and analysis of wet etching process for micro electro-mechanical systems","authors":"O. Tabata, K. Shimaoka, S. Sugiyama","doi":"10.1109/MEMSYS.1991.114776","DOIUrl":"https://doi.org/10.1109/MEMSYS.1991.114776","url":null,"abstract":"Details of the etching of polysilicon sacrificial layers using a KOH etching solution have been studied. Etching rates showed strong dependence on KOH concentration and the structure pattern of the layers. For the clarification of the etching process, in situ observation of an etching process for various micro-membrane structures with polysilicon sacrificial layers has been done. Etching observation equipment was created for this purpose. The equipment is capable of monitoring and recording the etching process in situ under various etching conditions such as temperatures, flow rates and concentrations. It is shown from in situ observation that hydrogen bubbles play an important role in supplying fresh etching solution to the surface to be etched away. Repeated accumulation and exhaust of hydrogen bubbles cause strong oscillatory movement of the membrane structures. This movement results in the fracture of the membrane due to the increase in membrane stress. Based on these results, a system for in situ observation and stress analysis of a wet etching process is proposed.<<ETX>>","PeriodicalId":258054,"journal":{"name":"[1991] Proceedings. IEEE Micro Electro Mechanical Systems","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1991-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114986473","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 : 1991-01-30DOI: 10.1109/MEMSYS.1991.114796
T. Bloomstein, D. Ehrlich
A patterning machine capable of 5*10/sup 4/ pixel per second random access scanning has been developed as a tool for laser microchemical fabrication of three-dimensional parts. The tool is designed to implement precision laser deposition and etching reactions through a direct interface to solid modeling CAD/CAM (computer-aided design/manufacturing) software. Initial results with the three-dimensional laser patterning machine demonstrate clean etching of germanium and silicon with micrometer depth control and speeds one to two orders of magnitude faster than electric discharge machining. High material selectivity has been exploited to write buried flow channels under oxide membranes.<>
{"title":"Laser-chemical three-dimensonal writing of multimaterial structures for microelectromechanics","authors":"T. Bloomstein, D. Ehrlich","doi":"10.1109/MEMSYS.1991.114796","DOIUrl":"https://doi.org/10.1109/MEMSYS.1991.114796","url":null,"abstract":"A patterning machine capable of 5*10/sup 4/ pixel per second random access scanning has been developed as a tool for laser microchemical fabrication of three-dimensional parts. The tool is designed to implement precision laser deposition and etching reactions through a direct interface to solid modeling CAD/CAM (computer-aided design/manufacturing) software. Initial results with the three-dimensional laser patterning machine demonstrate clean etching of germanium and silicon with micrometer depth control and speeds one to two orders of magnitude faster than electric discharge machining. High material selectivity has been exploited to write buried flow channels under oxide membranes.<<ETX>>","PeriodicalId":258054,"journal":{"name":"[1991] Proceedings. IEEE Micro Electro Mechanical Systems","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1991-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123117007","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 : 1991-01-30DOI: 10.1109/MEMSYS.1991.114769
T. Furuhata, T. Hirano, K. J. Gabriel, H. Fujita
The authors present a processing technique consisting of polysilicon etching, thermal oxidation of polysilicon, and silicon dioxide wet-etching which results in the fabrication of operational, submicron gaps between the electrodes of side-drive actuators, without the need for submicron etching capability. As one example of an application of oxidation machining, this technique was used to define operational submicron gaps between the polysilicon electrodes of an electrostatic comb-drive actuator and a type of linear, side-drive actuator. Experimental results have verified the fundamental principle of the fabrication and indicate that it is possible to achieve operational gaps as small as 0.2 mu m with 10,000 AA resolution.<>
{"title":"Sub-micron gaps without sub-micron etching","authors":"T. Furuhata, T. Hirano, K. J. Gabriel, H. Fujita","doi":"10.1109/MEMSYS.1991.114769","DOIUrl":"https://doi.org/10.1109/MEMSYS.1991.114769","url":null,"abstract":"The authors present a processing technique consisting of polysilicon etching, thermal oxidation of polysilicon, and silicon dioxide wet-etching which results in the fabrication of operational, submicron gaps between the electrodes of side-drive actuators, without the need for submicron etching capability. As one example of an application of oxidation machining, this technique was used to define operational submicron gaps between the polysilicon electrodes of an electrostatic comb-drive actuator and a type of linear, side-drive actuator. Experimental results have verified the fundamental principle of the fabrication and indicate that it is possible to achieve operational gaps as small as 0.2 mu m with 10,000 AA resolution.<<ETX>>","PeriodicalId":258054,"journal":{"name":"[1991] Proceedings. IEEE Micro Electro Mechanical Systems","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1991-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125165354","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 : 1991-01-30DOI: 10.1109/MEMSYS.1991.114771
W. Menz, W. Bacher, M. Harmening, Andreas Michel
The LIGA technique originally developed to fabricate separation nozzles for the enrichment of uranium has been expanded into a universal technology for the fabrication of microstructures with high aspect ratio and free lateral shaping. The LIGA process consists of three basic process steps: deep-etch lithography by means of synchrotron radiation, electroforming, and plastic molding. The choice of materials ranges from plastics (PMMA, POM, PA) to metals (up to now Au, Ni, Cu) and ceramics (ZrO/sub 2/). These microstructures can be mass-produced by inexpensive injection molding and reaction injection molding processes. Integration with Si technology/int is possible, opening up the potential of novel applications and improving both overall yield and package density.<>
{"title":"The LIGA technique-A novel concept for microstructures and the combination with Si-technologies by injection molding","authors":"W. Menz, W. Bacher, M. Harmening, Andreas Michel","doi":"10.1109/MEMSYS.1991.114771","DOIUrl":"https://doi.org/10.1109/MEMSYS.1991.114771","url":null,"abstract":"The LIGA technique originally developed to fabricate separation nozzles for the enrichment of uranium has been expanded into a universal technology for the fabrication of microstructures with high aspect ratio and free lateral shaping. The LIGA process consists of three basic process steps: deep-etch lithography by means of synchrotron radiation, electroforming, and plastic molding. The choice of materials ranges from plastics (PMMA, POM, PA) to metals (up to now Au, Ni, Cu) and ceramics (ZrO/sub 2/). These microstructures can be mass-produced by inexpensive injection molding and reaction injection molding processes. Integration with Si technology/int is possible, opening up the potential of novel applications and improving both overall yield and package density.<<ETX>>","PeriodicalId":258054,"journal":{"name":"[1991] Proceedings. IEEE Micro Electro Mechanical Systems","volume":"399 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1991-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126038371","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 : 1991-01-30DOI: 10.1109/MEMSYS.1991.114775
A. Hanneborg
Different bonding techniques under development for assembly of micromechanical elements are reviewed. A versatile wafer-to-wafer bonding process using silicon-to-silicon anodic bonding with sputtered Pyrex 7740 borosilicate thin film has been developed. The method gives sealings with a bonding strength of approximately 2.5*10/sup 6/N/m/sup 2/ and excellent thermal matching, resulting in minimized thermally induced stress in micromechanical components. The anodic bonding is performed at temperatures well below the aluminum/silicon eutectic temperature, making the process suitable also for metallized wafers. The large electrostatic force obtained during bonding is crucial for a high-yield wafer-to-wafer bonding process. High bonding strength and complete bonding of 3-in wafers were obtained. This technique was used for a silicon pressure sensor application, giving excellent thermal and long term stability for this sensor. The results are supported by finite-element calculations.<>
{"title":"Silicon wafer bonding techniques for assembly of micromechanical elements","authors":"A. Hanneborg","doi":"10.1109/MEMSYS.1991.114775","DOIUrl":"https://doi.org/10.1109/MEMSYS.1991.114775","url":null,"abstract":"Different bonding techniques under development for assembly of micromechanical elements are reviewed. A versatile wafer-to-wafer bonding process using silicon-to-silicon anodic bonding with sputtered Pyrex 7740 borosilicate thin film has been developed. The method gives sealings with a bonding strength of approximately 2.5*10/sup 6/N/m/sup 2/ and excellent thermal matching, resulting in minimized thermally induced stress in micromechanical components. The anodic bonding is performed at temperatures well below the aluminum/silicon eutectic temperature, making the process suitable also for metallized wafers. The large electrostatic force obtained during bonding is crucial for a high-yield wafer-to-wafer bonding process. High bonding strength and complete bonding of 3-in wafers were obtained. This technique was used for a silicon pressure sensor application, giving excellent thermal and long term stability for this sensor. The results are supported by finite-element calculations.<<ETX>>","PeriodicalId":258054,"journal":{"name":"[1991] Proceedings. IEEE Micro Electro Mechanical Systems","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1991-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115203170","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 : 1991-01-30DOI: 10.1109/MEMSYS.1991.114804
N. Kami‐ike, S. Kudo, Y. Magariyama, S. Aizawa, H. Hotani
Bacterial cells possess ultra-small motors on their surfaces with which to rotate their flagellar filaments. The motor utilizes the electrochemical energy stored in the proton gradient across the cytoplasmic membrane, and can rotate at more than 200 r.p.s. without a load. It can rotate in both clockwise and counterclockwise directions and switch the rotational direction in 1 msec. Its rotator is made of about 10 kinds of proteins and is about 30 nm in diameter. To analyze the motor function in detail, the authors have developed a laser dark-field microscopy technique by which high-speed rotation of a single flagellum can be measured. They have also succeeded in controlling the rotation speed by applying an external electric pulse to a bacterial cell that is held at the tip of a micropipette.<>
{"title":"Characteristics of an ultra-small biomotor","authors":"N. Kami‐ike, S. Kudo, Y. Magariyama, S. Aizawa, H. Hotani","doi":"10.1109/MEMSYS.1991.114804","DOIUrl":"https://doi.org/10.1109/MEMSYS.1991.114804","url":null,"abstract":"Bacterial cells possess ultra-small motors on their surfaces with which to rotate their flagellar filaments. The motor utilizes the electrochemical energy stored in the proton gradient across the cytoplasmic membrane, and can rotate at more than 200 r.p.s. without a load. It can rotate in both clockwise and counterclockwise directions and switch the rotational direction in 1 msec. Its rotator is made of about 10 kinds of proteins and is about 30 nm in diameter. To analyze the motor function in detail, the authors have developed a laser dark-field microscopy technique by which high-speed rotation of a single flagellum can be measured. They have also succeeded in controlling the rotation speed by applying an external electric pulse to a bacterial cell that is held at the tip of a micropipette.<<ETX>>","PeriodicalId":258054,"journal":{"name":"[1991] Proceedings. IEEE Micro Electro Mechanical Systems","volume":"387 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1991-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115481521","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 : 1991-01-30DOI: 10.1109/MEMSYS.1991.114807
G. Fuhr, R. Hagedorn, T. Muller, B. Wagner, W. Benecke
Arrangements of microelectrodes as obtained by a microfabrication technique are found to be well suited for a linear transfer of microscopic particles such as biological cells and other objects of microscopic dimensions. The conditions for an effective manipulation of the particles are electrode geometries which correspond to the dimensions of the particle and adapted electrical excitation of the electrodes (traveling high-frequency waves). The motion of particles was found to be a super-position of dielectrophoresis and charge relaxation processes as they are dominant, e.g. in dielectric induction motors. Microparticle velocities of some hundreds mu /s could be achieved by applying phase-shifted rectangular pulses with amplitudes between 5 and 15 volts.<>
通过微加工技术获得的微电极排列被发现非常适合于微观颗粒的线性转移，如生物细胞和其他微观尺寸的物体。有效操纵粒子的条件是电极的几何形状，其与粒子的尺寸相对应，并适应电极的电激励(行高频波)。粒子的运动被发现是介电电泳和电荷弛豫过程的叠加，因为它们占主导地位，例如在电介质感应电动机中。通过施加振幅在5到15伏之间的相移矩形脉冲，可以实现数百μ m /s的微粒速度。
{"title":"Linear motion of dielectric particles and living cells in microfabricated structures induced by traveling electric fields","authors":"G. Fuhr, R. Hagedorn, T. Muller, B. Wagner, W. Benecke","doi":"10.1109/MEMSYS.1991.114807","DOIUrl":"https://doi.org/10.1109/MEMSYS.1991.114807","url":null,"abstract":"Arrangements of microelectrodes as obtained by a microfabrication technique are found to be well suited for a linear transfer of microscopic particles such as biological cells and other objects of microscopic dimensions. The conditions for an effective manipulation of the particles are electrode geometries which correspond to the dimensions of the particle and adapted electrical excitation of the electrodes (traveling high-frequency waves). The motion of particles was found to be a super-position of dielectrophoresis and charge relaxation processes as they are dominant, e.g. in dielectric induction motors. Microparticle velocities of some hundreds mu /s could be achieved by applying phase-shifted rectangular pulses with amplitudes between 5 and 15 volts.<<ETX>>","PeriodicalId":258054,"journal":{"name":"[1991] Proceedings. IEEE Micro Electro Mechanical Systems","volume":"37 2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1991-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122450899","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 : 1991-01-30DOI: 10.1109/MEMSYS.1991.114772
K. Guckel, K. Skrobis, T. R. Christenson, J. Klein, S. Han, Bumkyoo Choi, E. G. Lovell
A variant of deep X-ray lithography, the LIGA process, is described. The fundamental processing sequence has been augmented with a locally defined sacrificial polyimide layer. This requires alignment of the X-ray mask to the optically defined sacrificial pattern via specially developed align-and-clamping jigs. The end results of this process are either fully unsupported metal structures or components which are locally attached to the substrate. Attempts to use this type of processing to produce assembled devices have been successful. Thus, free gears and fully attached shafts have been connected to form a nickel gear box. More complex assembly experiments have been completed successfully and are encouraging enough to pursue this approach further.<>
{"title":"Fabrication of assembled micromechanical components via deep X-ray lithography","authors":"K. Guckel, K. Skrobis, T. R. Christenson, J. Klein, S. Han, Bumkyoo Choi, E. G. Lovell","doi":"10.1109/MEMSYS.1991.114772","DOIUrl":"https://doi.org/10.1109/MEMSYS.1991.114772","url":null,"abstract":"A variant of deep X-ray lithography, the LIGA process, is described. The fundamental processing sequence has been augmented with a locally defined sacrificial polyimide layer. This requires alignment of the X-ray mask to the optically defined sacrificial pattern via specially developed align-and-clamping jigs. The end results of this process are either fully unsupported metal structures or components which are locally attached to the substrate. Attempts to use this type of processing to produce assembled devices have been successful. Thus, free gears and fully attached shafts have been connected to form a nickel gear box. More complex assembly experiments have been completed successfully and are encouraging enough to pursue this approach further.<<ETX>>","PeriodicalId":258054,"journal":{"name":"[1991] Proceedings. IEEE Micro Electro Mechanical Systems","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1991-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124113410","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 : 1991-01-30DOI: 10.1109/MEMSYS.1991.114767
S. Jacobsen, D. L. Wells, C. C. Davis, J. Wood
The authors present specific nonplanar lithographic (NPL) techniques for use in fabricating both monolithic micromachines and microcomponents for use in larger systems. The emphasis is on the use of numerically controlled E-beam-based lithography, with the resist exposed over nonplanar surfaces. Previously, nonplanar, optical-mask-based approaches have been used to fabricate devices such as wobble motor rotors, but with less success than the NPL techniques due to depth-of-field problems. The specific focus is on etching cylindrically shaped metal structures which are either (1) homogeneous or (2) layered by successive deposition, masking, and etching. Structures on the order of 80 to 500 microns in diameter have been constructed of either solid metals or sputtered thin metallic layers on quartz shafts. A number of either deep or shallow patterns have been fabricated on and through the structures, with promising results. Examples include helices, longitudinal lines, holes, notches, flexures, barbs, alphanumeric characters, and electrostatic field emitting patterns for use in wobble motors. Efforts are now proceeding toward generating complete systems, including transducers and actuators for industrial and medical applications.<>
{"title":"Fabrication of micro-structures using non-planar lithography (NPL)","authors":"S. Jacobsen, D. L. Wells, C. C. Davis, J. Wood","doi":"10.1109/MEMSYS.1991.114767","DOIUrl":"https://doi.org/10.1109/MEMSYS.1991.114767","url":null,"abstract":"The authors present specific nonplanar lithographic (NPL) techniques for use in fabricating both monolithic micromachines and microcomponents for use in larger systems. The emphasis is on the use of numerically controlled E-beam-based lithography, with the resist exposed over nonplanar surfaces. Previously, nonplanar, optical-mask-based approaches have been used to fabricate devices such as wobble motor rotors, but with less success than the NPL techniques due to depth-of-field problems. The specific focus is on etching cylindrically shaped metal structures which are either (1) homogeneous or (2) layered by successive deposition, masking, and etching. Structures on the order of 80 to 500 microns in diameter have been constructed of either solid metals or sputtered thin metallic layers on quartz shafts. A number of either deep or shallow patterns have been fabricated on and through the structures, with promising results. Examples include helices, longitudinal lines, holes, notches, flexures, barbs, alphanumeric characters, and electrostatic field emitting patterns for use in wobble motors. Efforts are now proceeding toward generating complete systems, including transducers and actuators for industrial and medical applications.<<ETX>>","PeriodicalId":258054,"journal":{"name":"[1991] Proceedings. IEEE Micro Electro Mechanical Systems","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1991-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114755282","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 : 1991-01-30DOI: 10.1109/MEMSYS.1991.114794
F. Shimokawa, A. Furuya, S. Matsui
A dry etching technique using a newly proposed magnetically controlled reactive ion etching (MC-RIE) system to achieve fast and extremely selective polyimide etching is investigated. In this etching system, the etching parameters such as RF power, self-bias voltage, and gas pressure can be independently controlled by maintaining the plasma conditions. The self-bias voltage (ion accelerating energy) can be reduced to 30 V by using a plasma density (>1*10/sup 11/ cm/sup 3/) ten times higher than that of the conventional magnetron enhanced reactive ion etching (M-RIE) system. Etching rates up to 5 mu m/min are obtained under the following conditions: an oxygen gas pressure of 0.8 Pa, a self-bias voltage of about -60 V, and an RF power of 300 W. A Ti etching mask is found to have the highest selectivity of about 1000 from MC-RIE using O/sub 2/ gas. It is also found that increases in the selectivity (3000) and the etching rate are observed after 25% N/sub 2/ is added into the O/sub 2/ gas. Highly anisotropic etching with an aspect ratio of more than 10 in a 2 mu m line pattern was achieved. The polyimide etched surface is smooth and the surface roughness is less than 0.1 mu m.<>
{"title":"Fast and extremely selective polyimide etching with a magnetically controlled reactive ion etching system","authors":"F. Shimokawa, A. Furuya, S. Matsui","doi":"10.1109/MEMSYS.1991.114794","DOIUrl":"https://doi.org/10.1109/MEMSYS.1991.114794","url":null,"abstract":"A dry etching technique using a newly proposed magnetically controlled reactive ion etching (MC-RIE) system to achieve fast and extremely selective polyimide etching is investigated. In this etching system, the etching parameters such as RF power, self-bias voltage, and gas pressure can be independently controlled by maintaining the plasma conditions. The self-bias voltage (ion accelerating energy) can be reduced to 30 V by using a plasma density (>1*10/sup 11/ cm/sup 3/) ten times higher than that of the conventional magnetron enhanced reactive ion etching (M-RIE) system. Etching rates up to 5 mu m/min are obtained under the following conditions: an oxygen gas pressure of 0.8 Pa, a self-bias voltage of about -60 V, and an RF power of 300 W. A Ti etching mask is found to have the highest selectivity of about 1000 from MC-RIE using O/sub 2/ gas. It is also found that increases in the selectivity (3000) and the etching rate are observed after 25% N/sub 2/ is added into the O/sub 2/ gas. Highly anisotropic etching with an aspect ratio of more than 10 in a 2 mu m line pattern was achieved. The polyimide etched surface is smooth and the surface roughness is less than 0.1 mu m.<<ETX>>","PeriodicalId":258054,"journal":{"name":"[1991] Proceedings. IEEE Micro Electro Mechanical Systems","volume":"737 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1991-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128045460","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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