- Email: [email protected]
On the nature of the disordered layer produced by ion implantation
World Abstracts on Microelectronics and Reliability When considering the ways a substrate can be populated with chips, there appear to be only two alternatives, mount the chips face up, or face down. The latter method, although very attractive for lhe TAB technology, presents a number of technical roadblocks and will therefore not be further discussed in this writing. The first method, face up mounting, requires that the leads be brought down to the substrate surface prior to bonding. This operation, referred to here as lead forming, requires careful consideration of the desired lead trajectory, which in turn affects the tape lead design. Because the tape is generally laid out in a regular pattern, the substrate bonding pads, which are mated to the formed leads must also be placed this way. This requirement will affect the entire design of the hybrid. This paper will describe how the Honeywell TAB team approached the design problem and developed a set of standards which were subsequently incorporated by the Jade Corporation in outer lead bonding tooling.
High Range low cost resistor system. RICHARD L. WAHLERS and KENNETH M. ML~Z. Proc. IEEE 28th Electron. Components Conf., Anaheim, 24-26 April 1978, p. 72. Processing and performance characteristics of a newly developed non-noble metal resistor glaze system compatible with both copper and nickel terminations and having 200 ppm/°C TCR capability over the range of 1 K ohm/square
9. E L E C T R O N ,
ION
AND
to 2 M ohm/square are presented. This new system based on a tantalum modified tin oxide conductive phase was developed to compliment the refractory metal screening glaze system (10 ohm/square-5 K ohm/square), described in a 1971 Electronic Components Conference paper.
High accuracy hybrid type 12-bit D - A converter made of TaAI-N thin film resistors. KATSUHIKO WATANABE, SEI1CHI KAWAMATAand Rvolcm KOZAKI. Proc. IEEE 28th Electron. Components Conf., Anaheim, 24-26 April 1978, p. 253. The most significant concern in designing high-resolution converters is the guarantee of accuracy, or distribution of error. The authors have established a method for minimizing temperature and long-term drifts of converter characterist i c s - k e y factors to guarantee converter accuracy--using hybrid techniques. The method uses (1) a TaAI-N thin film resistor with excellent thermal tracking ability and stability, sputtered onto a Fine Grain Aluminum Substrate (FGA Substrat¢) having superb thermal conductivity and surface smoothness, and (2) 3-stage functional trimming using a YAG laser for negligible initial errors. With these techniques, construction of a complete and adjustment-free 12-bit D-A converter has been achieved. This paper describes circuit design, hybrid construction, accuracy analysis, and the production process for this high-resolution converter.
LASER
Reducing post trim drift of thin film resistors by optimizing YAG laser output characteristics. ROBERT DOW, MICHAEL MAUCK, THOMAS RICHARDSON and EDWARD SWENSON. Proc. IEEE 28th Electron. Components Conf., Anaheim, 24-26 April 1978, p. 87. The pressure to increase stability and reduce the size of tantalum nitride resistor networks necessitates the further improvement of the laser trimming process. Bulger I has" mathematically modeled a tantalum nitride thin film resistor and concluded that the major cause of post trim drift of a laser trimmed resistor is due to the heat affected zone bordering the kerr. We have postulated that very short pulses would reduce the heat affected zone and reduce resistor drift. Others 2,a have suggested that lasers operating in the green region of the visible spectrum could provide improvement. The objective of this study is to experimentally determine the effects of laser parameters on the heat affected zone and resulting resistor stability. The salient properties of the laser system are first characterized. Then, the present work postulates a model for the heat affected zone and experimentally examines what effect the laser parameters have on resistor drift. Specific studies involved varying laser pulse width, power, wavelength, repetition rate, and waist size. A simple analytic procedure is used to compare the properties of the variously trimmed resistors. The acousto-optically Q-switched Nd : YAG laser operating at a wavelength of 1064 nanometers is the most commonly used laser for resistor trimming applications and was used as the basic laser for this study. A second harmonic generator was addecl to provide green (532.0 nanometer) wavelength. Also a pulse slicer was employed to shorten the standard YAG pulses.
415
BEAM
TECHNIQUES
On the nature of the disordered layer produced by ion implantation. K. ZELLAMA,P. GERMAIN, S. SOUELARD and J. C. BOURC-OIN.Solid St. Commun. 26, 901 (1978)~ The aim of this communication is to compare some thermodynamic parameters measured in amorphous layers produced by evaporation and in disordered layers produced by ion implantation (which will be called implanted layers). The thermodynamics parameters studied are: the temperature of the annealing stages (reflecting the activation energies for atomic rearrangement) and the activation energy of the growth rate for crystallization. This investigation has been performed in germanium because the crystallization in this material has been extensively studied.
Ion implantation in amorphous germanium and silicon. P. SEKHAR,M. C. JOSHI, K. L. NARASIMHANand S. GUHA. Solid St. Commun. 26, 933 (1978). The effects of Sb and AI implantation on the conductivity of amorphous Ge and Si film are reported. The room temperature conductivity of the vacuum deposited films is found to increase by a factor of 50 to 100 on implantation. The excess conductivity can be removed by annealing at 300°C for 6 hr. Results on ct-Si films deposited in a partial pressure of H2 also indicate that doping effect due to ion implantation is very small. The temperature dependence of conductivity of the films is found to obey a T - l / a law before and after implantation. The value of To is found to be rather insensitive to both hydrogenation and implantation.
High Range low cost resistor system. RICHARD L. WAHLERS and KENNETH M. ML~Z. Proc. IEEE 28th Electron. Components Conf., Anaheim, 24-26 April 1978, p. 72. Processing and performance characteristics of a newly developed non-noble metal resistor glaze system compatible with both copper and nickel terminations and having 200 ppm/°C TCR capability over the range of 1 K ohm/square
9. E L E C T R O N ,
ION
AND
to 2 M ohm/square are presented. This new system based on a tantalum modified tin oxide conductive phase was developed to compliment the refractory metal screening glaze system (10 ohm/square-5 K ohm/square), described in a 1971 Electronic Components Conference paper.
High accuracy hybrid type 12-bit D - A converter made of TaAI-N thin film resistors. KATSUHIKO WATANABE, SEI1CHI KAWAMATAand Rvolcm KOZAKI. Proc. IEEE 28th Electron. Components Conf., Anaheim, 24-26 April 1978, p. 253. The most significant concern in designing high-resolution converters is the guarantee of accuracy, or distribution of error. The authors have established a method for minimizing temperature and long-term drifts of converter characterist i c s - k e y factors to guarantee converter accuracy--using hybrid techniques. The method uses (1) a TaAI-N thin film resistor with excellent thermal tracking ability and stability, sputtered onto a Fine Grain Aluminum Substrate (FGA Substrat¢) having superb thermal conductivity and surface smoothness, and (2) 3-stage functional trimming using a YAG laser for negligible initial errors. With these techniques, construction of a complete and adjustment-free 12-bit D-A converter has been achieved. This paper describes circuit design, hybrid construction, accuracy analysis, and the production process for this high-resolution converter.
LASER
Reducing post trim drift of thin film resistors by optimizing YAG laser output characteristics. ROBERT DOW, MICHAEL MAUCK, THOMAS RICHARDSON and EDWARD SWENSON. Proc. IEEE 28th Electron. Components Conf., Anaheim, 24-26 April 1978, p. 87. The pressure to increase stability and reduce the size of tantalum nitride resistor networks necessitates the further improvement of the laser trimming process. Bulger I has" mathematically modeled a tantalum nitride thin film resistor and concluded that the major cause of post trim drift of a laser trimmed resistor is due to the heat affected zone bordering the kerr. We have postulated that very short pulses would reduce the heat affected zone and reduce resistor drift. Others 2,a have suggested that lasers operating in the green region of the visible spectrum could provide improvement. The objective of this study is to experimentally determine the effects of laser parameters on the heat affected zone and resulting resistor stability. The salient properties of the laser system are first characterized. Then, the present work postulates a model for the heat affected zone and experimentally examines what effect the laser parameters have on resistor drift. Specific studies involved varying laser pulse width, power, wavelength, repetition rate, and waist size. A simple analytic procedure is used to compare the properties of the variously trimmed resistors. The acousto-optically Q-switched Nd : YAG laser operating at a wavelength of 1064 nanometers is the most commonly used laser for resistor trimming applications and was used as the basic laser for this study. A second harmonic generator was addecl to provide green (532.0 nanometer) wavelength. Also a pulse slicer was employed to shorten the standard YAG pulses.
415
BEAM
TECHNIQUES
On the nature of the disordered layer produced by ion implantation. K. ZELLAMA,P. GERMAIN, S. SOUELARD and J. C. BOURC-OIN.Solid St. Commun. 26, 901 (1978)~ The aim of this communication is to compare some thermodynamic parameters measured in amorphous layers produced by evaporation and in disordered layers produced by ion implantation (which will be called implanted layers). The thermodynamics parameters studied are: the temperature of the annealing stages (reflecting the activation energies for atomic rearrangement) and the activation energy of the growth rate for crystallization. This investigation has been performed in germanium because the crystallization in this material has been extensively studied.
Ion implantation in amorphous germanium and silicon. P. SEKHAR,M. C. JOSHI, K. L. NARASIMHANand S. GUHA. Solid St. Commun. 26, 933 (1978). The effects of Sb and AI implantation on the conductivity of amorphous Ge and Si film are reported. The room temperature conductivity of the vacuum deposited films is found to increase by a factor of 50 to 100 on implantation. The excess conductivity can be removed by annealing at 300°C for 6 hr. Results on ct-Si films deposited in a partial pressure of H2 also indicate that doping effect due to ion implantation is very small. The temperature dependence of conductivity of the films is found to obey a T - l / a law before and after implantation. The value of To is found to be rather insensitive to both hydrogenation and implantation.