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Charge coupled devices—basic operation and principles
212
World Abstracts on Microelectronics and Reliability
On the reliability analysis of complex systems. A. G. COLOMBO. Microelectron. Reliab. 15, 459 (1976). Reliability analysis of a complex system is characterized by three fundamental and interconnected aspects: system description, calculation method and computer program. The paper discusses the main features of various approaches. Emphasis is given to some analysis techniques oriented to fault-tree representation and cut set approximation.
Prediction of future failures of a system. T. LwIN and N. SINGH. Microelectron. Reliab. 15. 485 (1976). One of the main problems in probabilistic reliability theory is to obtain the "survival probability function" of a "system", based on the survival probability function of each of a set of "components" that constitute the system. For simple standard systems this problem has been explicitly solved and exact solutions have been obtained. For more complicated systems (i.e. a general complex system), however, solutions can be obtained at most approximately.
A parallel and related problem is that of the statistical (inferential) reliability theory which is concerned with estimating the system survival probability based on estimates of the component, survival probability or based on observations on the "life-length" of components. This, of course, is a special case of the general problem of statistical estimation and substantial work is already done in this context. A second parallel problem which is closely related to the estimation theory is that of statistical prediction of the future life-length of a system. It is our opinion that a solution to this problem of statistical prediction is more relevant and pragmatic for functional purposes of the reliability engineering. This is not to imply that the estimation procedures are not necessary. On the contrary, the estimation theory is essential to prediction theory as a basic step in developing prediction procedures. The point to make here is that good estimation procedures should be exploited and further developed into prediction procedures for more relevant application in certain engineering areas.
4. M I C R O E L E C T R O N I C S ~ E N E R A L Charge coupled devices--basic operation and principles. R. K. ARORA.Microelectron. Reliab. 15, 475 (1976). Starting from the basic concepts involved, the different means for originating charge in a charge coupled device are reviewed. The basic charge transfer action is explained using 3-~b clocking scheme. A comparison is made with regards to fabrication and charge transfer efficiency between the single level metallization structure and modified structures operated in different clocking schemes.
Metal-insulator-metal sandwich structures with anomalous properties. H. BIEDERMAN. Vacuum. 26 (12), 513. Sandwich structures of metal/insulator/metal layers (MIM) possessing anomalous properties have been studied extensively because of their possible application as switching devices or cold cathode emitters. When a small voltage (2-15 V)
is applied to the electrodes of a fresh MIM sample, a forming process occurs. When this process is complete the electrical conductivity of a sample is raised by a few orders of magnitude and its I - V , characteristic shows a maximum in current. Simultaneously electron emission in vacuum, electroluminescence and switching effects can be observed and the sample shows a dependence in its electrical characteristics on the temperature and the nature of the gas atmosphere. All of the foregoing phenomena arc described and discussed and published experimental results reviewed. Theoretical models suggested by various workers consider on the one hand electrons to penetrate homogenously through the dielectric of the insulating layer, and on the other the passage of current by means of conductive filaments. These concepts are also reviewed and discussed. In conclusion, recent attempts to find an explanation of the anomalous behaviour are presented.
5. M I C R O E L E C T R O N I C S DESIGN AND C O N S T R U C T I O N Experiences in making original photomasks with micron-size features on the ANR 4 Automatic Nine-Barrel Repeater of VEB Carl Zeiss JENA. (Part 1). WALTER GARTNER. J E N A Review 1977/1 p. 12. The result of generating micron-sized pattern features, especially in the limiting range around 1 #m, is of a complex nature that is influenced by a great many factors--physical, technical and process engineering ones. Among them, some have a more particular effect on pattern and mask quality, viz: lens performance, barrel adjustment, photoplate qualities, photoplate processing, pattern topology and reticle quality. The first four of these influences have been largely investigated into at JENA during recent years. As a result, significant improvement in the rendition of micron-sized features has been achieved.
Planar magnetron sputtering; a new industrial coating technique. TED VAN VOROUS.Solid St. Teehnol. p. 62 (December 1976). The Planar Magnetron process is briefly described as it relates to current and future system design. The linear chamber design concept with rectangular cathodes is presented. Advantages and operating characteristics of these systems are covered.
Microprocessor automated sputtering. MARVIN HUTT. Solid St. Technol. p. 74 (December 1976). A distinction is drawn between pseudo-automation and true automation. The features of a truly automated system are outlined, and the design of an ideal automated sputtering machine is discussed. The value and functions of a microprocessor as a part of the automated system are presented.
Spin-on diffusion sources. MILTON GENSER. Proc. Internepcon. Microelectron. '76. Brighton. p. 102 (October 19-21, 1976). The advantage promised by the spin-on sources is the elimination of gas flow dynamics as a limiting factor in lot size and uniformity of doping parameters. A secondary, though important, advantage is the ability to achieve doping levels lower than the solid solubility of the specific element in silicon, such as is required in producing doping profiles for bases of transistors and in producing various diffused resistors in ICs. Additionally, with such elements as arsenic and antimony, the spin-on sources reduce personnel and air pollution hazards associated with handling large quantities of these poisonous materials. These are the general advantages offered by the spin-on sources. More subtle considerations related to the specific device have also lead to their use, eg the use of arsenic in NMOS where the smaller diffusion coefficient of arsenic results in less lateral spreading to permit designs with smaller channel lengths.
World Abstracts on Microelectronics and Reliability
On the reliability analysis of complex systems. A. G. COLOMBO. Microelectron. Reliab. 15, 459 (1976). Reliability analysis of a complex system is characterized by three fundamental and interconnected aspects: system description, calculation method and computer program. The paper discusses the main features of various approaches. Emphasis is given to some analysis techniques oriented to fault-tree representation and cut set approximation.
Prediction of future failures of a system. T. LwIN and N. SINGH. Microelectron. Reliab. 15. 485 (1976). One of the main problems in probabilistic reliability theory is to obtain the "survival probability function" of a "system", based on the survival probability function of each of a set of "components" that constitute the system. For simple standard systems this problem has been explicitly solved and exact solutions have been obtained. For more complicated systems (i.e. a general complex system), however, solutions can be obtained at most approximately.
A parallel and related problem is that of the statistical (inferential) reliability theory which is concerned with estimating the system survival probability based on estimates of the component, survival probability or based on observations on the "life-length" of components. This, of course, is a special case of the general problem of statistical estimation and substantial work is already done in this context. A second parallel problem which is closely related to the estimation theory is that of statistical prediction of the future life-length of a system. It is our opinion that a solution to this problem of statistical prediction is more relevant and pragmatic for functional purposes of the reliability engineering. This is not to imply that the estimation procedures are not necessary. On the contrary, the estimation theory is essential to prediction theory as a basic step in developing prediction procedures. The point to make here is that good estimation procedures should be exploited and further developed into prediction procedures for more relevant application in certain engineering areas.
4. M I C R O E L E C T R O N I C S ~ E N E R A L Charge coupled devices--basic operation and principles. R. K. ARORA.Microelectron. Reliab. 15, 475 (1976). Starting from the basic concepts involved, the different means for originating charge in a charge coupled device are reviewed. The basic charge transfer action is explained using 3-~b clocking scheme. A comparison is made with regards to fabrication and charge transfer efficiency between the single level metallization structure and modified structures operated in different clocking schemes.
Metal-insulator-metal sandwich structures with anomalous properties. H. BIEDERMAN. Vacuum. 26 (12), 513. Sandwich structures of metal/insulator/metal layers (MIM) possessing anomalous properties have been studied extensively because of their possible application as switching devices or cold cathode emitters. When a small voltage (2-15 V)
is applied to the electrodes of a fresh MIM sample, a forming process occurs. When this process is complete the electrical conductivity of a sample is raised by a few orders of magnitude and its I - V , characteristic shows a maximum in current. Simultaneously electron emission in vacuum, electroluminescence and switching effects can be observed and the sample shows a dependence in its electrical characteristics on the temperature and the nature of the gas atmosphere. All of the foregoing phenomena arc described and discussed and published experimental results reviewed. Theoretical models suggested by various workers consider on the one hand electrons to penetrate homogenously through the dielectric of the insulating layer, and on the other the passage of current by means of conductive filaments. These concepts are also reviewed and discussed. In conclusion, recent attempts to find an explanation of the anomalous behaviour are presented.
5. M I C R O E L E C T R O N I C S DESIGN AND C O N S T R U C T I O N Experiences in making original photomasks with micron-size features on the ANR 4 Automatic Nine-Barrel Repeater of VEB Carl Zeiss JENA. (Part 1). WALTER GARTNER. J E N A Review 1977/1 p. 12. The result of generating micron-sized pattern features, especially in the limiting range around 1 #m, is of a complex nature that is influenced by a great many factors--physical, technical and process engineering ones. Among them, some have a more particular effect on pattern and mask quality, viz: lens performance, barrel adjustment, photoplate qualities, photoplate processing, pattern topology and reticle quality. The first four of these influences have been largely investigated into at JENA during recent years. As a result, significant improvement in the rendition of micron-sized features has been achieved.
Planar magnetron sputtering; a new industrial coating technique. TED VAN VOROUS.Solid St. Teehnol. p. 62 (December 1976). The Planar Magnetron process is briefly described as it relates to current and future system design. The linear chamber design concept with rectangular cathodes is presented. Advantages and operating characteristics of these systems are covered.
Microprocessor automated sputtering. MARVIN HUTT. Solid St. Technol. p. 74 (December 1976). A distinction is drawn between pseudo-automation and true automation. The features of a truly automated system are outlined, and the design of an ideal automated sputtering machine is discussed. The value and functions of a microprocessor as a part of the automated system are presented.
Spin-on diffusion sources. MILTON GENSER. Proc. Internepcon. Microelectron. '76. Brighton. p. 102 (October 19-21, 1976). The advantage promised by the spin-on sources is the elimination of gas flow dynamics as a limiting factor in lot size and uniformity of doping parameters. A secondary, though important, advantage is the ability to achieve doping levels lower than the solid solubility of the specific element in silicon, such as is required in producing doping profiles for bases of transistors and in producing various diffused resistors in ICs. Additionally, with such elements as arsenic and antimony, the spin-on sources reduce personnel and air pollution hazards associated with handling large quantities of these poisonous materials. These are the general advantages offered by the spin-on sources. More subtle considerations related to the specific device have also lead to their use, eg the use of arsenic in NMOS where the smaller diffusion coefficient of arsenic results in less lateral spreading to permit designs with smaller channel lengths.