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Improved slicing and orientation technique for I.D. sawing
World Abstracts on Microelectronics and Reliability
563
5. M I C R O E L E C T R O N I C S D E S I G N A N D C O N S T R U C T I O N Silicon epitaxial growth via dichlorosilane in a barrel reactor. Y. S. CHIANG. RCA Rev. 38, 500 (December 1977). This report presents the results of the study of silicon epitaxial growth using dichlorosilane in a large vertical barrel reactor. Thickness uniformity, surface quality, and resistivity control and uniformity of the epitaxial layers were studied and optimized in terms of the operating parameters of the system. Under the experimentally defined optimal conditions, thickness uniformity in the neighborhood of + 5 % is achieved for growth rates in the range of 2 to 6/~m/min. The resistivity of undoped layers on heavily doped n + substrates is equal to or exceeds 100ohm-cm. The doping control and resistivity uniformity are more than sufficient for growth of high-voltage device structures. Surface quality comparable to that obtained via silicon tetrachloride has been achieved. Planar Zn diffusion in lnP. E. A. REZEK, P. D. WRIGHT and N. HOLONYAK,JR. Solid-St. Electron. 21,325 (1978). A procedure for achieving well-behaved planar Zn diffusion to a controllable depth in n-type InP is described. The dilute-Zn diffusion, which utilizes a Zn + Ga + P source (in an evacuated ampoule), is performed in the temperature range 650~ 700°C. The low diffusion temperatures employed assure that any previous junctions that might be prepared, such as LPE heterojunctions, are not affected by the diffusion process. The masking afforded by Si3N,~ and partial "masking," or attenuation, afforded by S i O / o n InP are demonstrated. The results obtained suggest that dilute Zn diffusion in lnP, with a significant P over-pressure, favors a substitutional diffusion mechanism that probably follows a complementary error function distribution.
cluding lift-off pattern studies, clamped-wire studies, and bond deformation versus ultrasonic vibration amplitude studies, indicate that gold ultrasonic bonding takes place primarily by means of a deformation mechanism as opposed to a heating or sliding mechanism. This is substantially the same result previously obtained from studies on the aluminum ultrasonic bonding mechanism. Further, it is shown that a deformation mechanism also holds for other forms of solid phase microelectronic bonding. Specific examples are taken from electric discharge "tweezer welds" and from thermocompression bonds. The role of contaminant removal and certain reliability aspects of ultrasonic bonding are also discussed.
High temperature thermal characteristics of microelectronic packages. GENE K. BAXTER and JAMES W. ANSLOW. IEEE Trans. Parts, Hybrids, Packa~in,q PHP-13, (4) 385 (December 1977). This paper describes results of the computer-analysis portion of a research program which was conducted to study the thermal characteristics of microcircuits in high temperature environments. A special 1C chip, bonded to an alumina chip carrier, was modeled for these simulations. It was found that thermal resistance values and thermal time constants nearly double when the chip carrier temperature is increased from 70 to 257°C. For a chip power dissipation of 1.5 W, the peak junction temperature increased from 138 to 385°C, an increase of 247°C, while the chip carrier only increased by 187°C. The thermal time constant of the junction peak temperature rise, measured relative to the chip carrier, increased from 15 to 26 ps over the same temperature range.
Improved slicing and orientation technique for I.D. sawing. JOHANNES GRANDMAand J. CHARLES HILL. Solid St. Technol. p, 40 (February 1978), A new technique for cutting gadolinium gallium garnet wafers for substrates in bubble memory devices is described. This technique should also have application to slicing other substrate materials, such as sapphire and silicon. The method extends the useful life of I.D. diamond blades by a factor of seven and increases productivity substantially while decreasing cost.
A new moisture sensor for in situ monitoring of sealed packages. MICHAEL G. KOVA(', DAVID CHLECK and PHILIP GOODMAN. Solid St. Technol. p. 35 (February 1978). A new A1203 moisture sensor fabricated on an oxidized silicon wafer is described. The sensor responds to moisture levels down to 1 ppmv and is used to nondestructively determine the water level inside sealed hybrid packages. Device performance characteristics are given. Preliminary results are reported for these devices sealed in hybrid packages at several manufacturing locations.
The ultrasonic welding mechanism as applied to aluminumand gold-wire bonding in microelectronics. GEORGE G. HARMAN and JOHN ALBERS. IEEE Trans. Parts, Hybrids, Packa,qin9 PHP-13, (4) 406 (December 1977). This paper represents a review as well as an extension of previous work concerned with the mechanism of microelectronic ultrasonic welding for both aluminum and gold wires. A series of experiments was carried out to determine the mechanism of gold-to-gold ultrasonic bonding. These experiments, in-
Ellipsometry for semiconductor process control. R. J. K UTKO. Solid St. Technol. p. 43 (February 1978). General aspects of the powerful and elegant technique of ellipsometry are described. Emphasis is on the practical utilization of this method for measuring semiconductor films. Values are given for films and substrates likely to be encountered. Also discussed are recent new developments in data conversion and instrumentation such as calculators and fully automatic ellipsometers.
6. M I C R O E L E C T R O N I C S - - C O M P O N E N T S ,
Low-cost microcomputing: The personal computer and singleboard computer revolutions. JOHN DOERR. Proc. IEEE 66, (2) 117 (February 1978). Personal computing is one of the most revolutionary applications of microprocessors; singleboard computing is another. The origins of both applications are traced and current products and services described in a tutorial fashion. Trends are forecasted and conclusions drawn about these two low-cost computing revolutions. Spurious signal generation in plastic film capacitors. JON W. BOROUGH, JOHN BURNHAM, WILLIAM J. SIMMONS and SAMMIEL. WEBSTER.IEEE Trans. Parts, Hybrids, Packaging PHP-13, (4) 402 (December 1977). Plastic film capacitors with dielectric materials such as Mylar or polycarbonate have been observed to generate spurious signals which
SYSTEMS
AND
EQUIPMENTS
appear as small spikes in capacitor voltage in the range of 10-300 #V. Such transients repeat at intervals varying from fractions of a second to years, becoming more frequent during periods of temperature change. The tendency to produce this phenomenon can persist for the normal life of the capacitor, depending on thermal and electrical stresses encountered. The effect under study is not related to dielectric breakdown or corona discharge which are due to high electric stress. The observed transients can appear at the capacitor electrodes with either polarity during application of voltage as low as zero. The source of charge and energy for this phenomenon is dielectric absorption (DA) which is history dependant relating directly to the nature of the dielectric material. Materials with high DA such as Mylar are much
563
5. M I C R O E L E C T R O N I C S D E S I G N A N D C O N S T R U C T I O N Silicon epitaxial growth via dichlorosilane in a barrel reactor. Y. S. CHIANG. RCA Rev. 38, 500 (December 1977). This report presents the results of the study of silicon epitaxial growth using dichlorosilane in a large vertical barrel reactor. Thickness uniformity, surface quality, and resistivity control and uniformity of the epitaxial layers were studied and optimized in terms of the operating parameters of the system. Under the experimentally defined optimal conditions, thickness uniformity in the neighborhood of + 5 % is achieved for growth rates in the range of 2 to 6/~m/min. The resistivity of undoped layers on heavily doped n + substrates is equal to or exceeds 100ohm-cm. The doping control and resistivity uniformity are more than sufficient for growth of high-voltage device structures. Surface quality comparable to that obtained via silicon tetrachloride has been achieved. Planar Zn diffusion in lnP. E. A. REZEK, P. D. WRIGHT and N. HOLONYAK,JR. Solid-St. Electron. 21,325 (1978). A procedure for achieving well-behaved planar Zn diffusion to a controllable depth in n-type InP is described. The dilute-Zn diffusion, which utilizes a Zn + Ga + P source (in an evacuated ampoule), is performed in the temperature range 650~ 700°C. The low diffusion temperatures employed assure that any previous junctions that might be prepared, such as LPE heterojunctions, are not affected by the diffusion process. The masking afforded by Si3N,~ and partial "masking," or attenuation, afforded by S i O / o n InP are demonstrated. The results obtained suggest that dilute Zn diffusion in lnP, with a significant P over-pressure, favors a substitutional diffusion mechanism that probably follows a complementary error function distribution.
cluding lift-off pattern studies, clamped-wire studies, and bond deformation versus ultrasonic vibration amplitude studies, indicate that gold ultrasonic bonding takes place primarily by means of a deformation mechanism as opposed to a heating or sliding mechanism. This is substantially the same result previously obtained from studies on the aluminum ultrasonic bonding mechanism. Further, it is shown that a deformation mechanism also holds for other forms of solid phase microelectronic bonding. Specific examples are taken from electric discharge "tweezer welds" and from thermocompression bonds. The role of contaminant removal and certain reliability aspects of ultrasonic bonding are also discussed.
High temperature thermal characteristics of microelectronic packages. GENE K. BAXTER and JAMES W. ANSLOW. IEEE Trans. Parts, Hybrids, Packa~in,q PHP-13, (4) 385 (December 1977). This paper describes results of the computer-analysis portion of a research program which was conducted to study the thermal characteristics of microcircuits in high temperature environments. A special 1C chip, bonded to an alumina chip carrier, was modeled for these simulations. It was found that thermal resistance values and thermal time constants nearly double when the chip carrier temperature is increased from 70 to 257°C. For a chip power dissipation of 1.5 W, the peak junction temperature increased from 138 to 385°C, an increase of 247°C, while the chip carrier only increased by 187°C. The thermal time constant of the junction peak temperature rise, measured relative to the chip carrier, increased from 15 to 26 ps over the same temperature range.
Improved slicing and orientation technique for I.D. sawing. JOHANNES GRANDMAand J. CHARLES HILL. Solid St. Technol. p, 40 (February 1978), A new technique for cutting gadolinium gallium garnet wafers for substrates in bubble memory devices is described. This technique should also have application to slicing other substrate materials, such as sapphire and silicon. The method extends the useful life of I.D. diamond blades by a factor of seven and increases productivity substantially while decreasing cost.
A new moisture sensor for in situ monitoring of sealed packages. MICHAEL G. KOVA(', DAVID CHLECK and PHILIP GOODMAN. Solid St. Technol. p. 35 (February 1978). A new A1203 moisture sensor fabricated on an oxidized silicon wafer is described. The sensor responds to moisture levels down to 1 ppmv and is used to nondestructively determine the water level inside sealed hybrid packages. Device performance characteristics are given. Preliminary results are reported for these devices sealed in hybrid packages at several manufacturing locations.
The ultrasonic welding mechanism as applied to aluminumand gold-wire bonding in microelectronics. GEORGE G. HARMAN and JOHN ALBERS. IEEE Trans. Parts, Hybrids, Packa,qin9 PHP-13, (4) 406 (December 1977). This paper represents a review as well as an extension of previous work concerned with the mechanism of microelectronic ultrasonic welding for both aluminum and gold wires. A series of experiments was carried out to determine the mechanism of gold-to-gold ultrasonic bonding. These experiments, in-
Ellipsometry for semiconductor process control. R. J. K UTKO. Solid St. Technol. p. 43 (February 1978). General aspects of the powerful and elegant technique of ellipsometry are described. Emphasis is on the practical utilization of this method for measuring semiconductor films. Values are given for films and substrates likely to be encountered. Also discussed are recent new developments in data conversion and instrumentation such as calculators and fully automatic ellipsometers.
6. M I C R O E L E C T R O N I C S - - C O M P O N E N T S ,
Low-cost microcomputing: The personal computer and singleboard computer revolutions. JOHN DOERR. Proc. IEEE 66, (2) 117 (February 1978). Personal computing is one of the most revolutionary applications of microprocessors; singleboard computing is another. The origins of both applications are traced and current products and services described in a tutorial fashion. Trends are forecasted and conclusions drawn about these two low-cost computing revolutions. Spurious signal generation in plastic film capacitors. JON W. BOROUGH, JOHN BURNHAM, WILLIAM J. SIMMONS and SAMMIEL. WEBSTER.IEEE Trans. Parts, Hybrids, Packaging PHP-13, (4) 402 (December 1977). Plastic film capacitors with dielectric materials such as Mylar or polycarbonate have been observed to generate spurious signals which
SYSTEMS
AND
EQUIPMENTS
appear as small spikes in capacitor voltage in the range of 10-300 #V. Such transients repeat at intervals varying from fractions of a second to years, becoming more frequent during periods of temperature change. The tendency to produce this phenomenon can persist for the normal life of the capacitor, depending on thermal and electrical stresses encountered. The effect under study is not related to dielectric breakdown or corona discharge which are due to high electric stress. The observed transients can appear at the capacitor electrodes with either polarity during application of voltage as low as zero. The source of charge and energy for this phenomenon is dielectric absorption (DA) which is history dependant relating directly to the nature of the dielectric material. Materials with high DA such as Mylar are much