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Refractory metal silicon device technology
152
A B S T R A C T S ON M I C R O E L E C T R O N I C S AND R E L I A B I L I T Y
Epitaxial g r o w t h a n d growth defects. B. D. JOYCE,Electron. Compon., December (1968), p. 1389. Single crystal growth can be defined as a process involving a controlled phase change in a given material. In vapour growth the phases are solid and gaseous; the existence of an intermediate liquid phase has generally been disregarded except in work over the past few years. Vapour phase growth of materials has been known and utilized for a very long time but it is only in the past decade that these processes have been applied successfully to semiconductor materials.
Refractory metal silicon device technology. D. M. BROWN, W. E. ENGELER,~/I. GARFINKELand P. V. GRAY, Solid-St. Electron. 11 (1968), p. 1105. Films 2000-5000 A thick of Me or W deposited over thin films of thermally grown SiO 2 are shown to be effective high temperature diffusion masks against both phosphorus and boron. These metal films may be precisely patterned and their diffusion masking properties can be used to define the source and drain regions of MOSFETs. In this manner, selfregistered MOSFETs can be fabricated with a portion of the diffusion, masking metal film acting as the gate electrode. Using P or B doped deposited glasses as diffusion sources, n or p channel enhancement mode MOSFETs were made by diffusion through the exposed thin SiO 2 film intop and n type Si to form source and drain junctions. Contact was subsequently made by etching holes through the oxide layers to the source and drain regions and to the refractory metal gate electrode buried within the oxide layers. These devices exhibit channel mobilities between 200 and 300 cm ~ V-sec at gate voltages about 10 V above threshold. The stability of MOS structures processed in a similar manner has been measured. After being stressed at ± 6 × 105 V/cm and 250°C for 15 hr, these devices exhibited shifts in their C - V characteristics less than 200 mV. Measurement electronics for the three-polnt probe. P. A. SCHUMANN,JR., J. F. HALLENBACK,JR., M. R. POPONIAK and C. P. SCHNEIDER,Solid St. Technol., November (1968), p. 32. A review of the various techniques used to measure the breakdown voltage as determined by the three-point probe is presented. Descriptions are given of the a.c., d.c. pulse, and ramp systems with their variations. A new system involving a constant current ramp and electronic shut-off system is described and contrasted with previous techniques. The advantages and disadvantages of each system are described. Status of diffusion data in binary compound semiconductors. D. W. YARBROUGH,Solid St. Technol., November (1968), p. 23. A critical review of the literature is presented in an effort to establish the status of diffusion data in III-V compounds, II-VI compounds, and SiC. This report will be useful in providing a relatively complete review and bibliography of published diffusion data. Observed electrical behaviour for various impurities in binary compounds, the important temperature variation parameters for the diffusion coefficient, D o and E, and range of values for the diffusion coefficients of numerous species are tabulated. Those atomic species which produce anomalous concentration profiles in the binary semiconducting materials have been indicated. 4. THIN FILM CIRCUITS AND MATERIALS Tantalum films form reliable low cost circuits. D. R. TIBBETTS,Electron. Compon., May (1968), p. 551. In the case of the thin-film circuits described, all the resistors are made from a single film and adjustment needs to be carried out only where extreme accuracy is required. The film is deposited by a process of sputtering in vacuum which is inherently a very constant process. In fact, many people have failed to realize the true potentialities of sputtering because the degree of cleanliness in the sputtering system must approach that required for semiconductor processes. The same sputtering source can be made to give constant deposition conditions over a period of several months and all that is then required is a method of feeding substrates into the system one after the other. If the vacuum process is used solely to coat substrates with a continuous metal film in this way, a high throughput can be obtained and the cost of the vacuum stage is a negligible fraction of the overall cost. Hybrid thin film micro-electrouics--A quick and flexible method of micro-circuit construction. A. J. MARRIAGEand R. N. WHEATEN,Prec. I.R.E.E. Australia, May (1968), p. 137. Thin film integrated circuits can be made by depositing a pattern of resistive, dielectric and conductive materials on to an insulating substrate. The advantages and limitations of hybrid thin film micro-circuits are
A B S T R A C T S ON M I C R O E L E C T R O N I C S AND R E L I A B I L I T Y
Epitaxial g r o w t h a n d growth defects. B. D. JOYCE,Electron. Compon., December (1968), p. 1389. Single crystal growth can be defined as a process involving a controlled phase change in a given material. In vapour growth the phases are solid and gaseous; the existence of an intermediate liquid phase has generally been disregarded except in work over the past few years. Vapour phase growth of materials has been known and utilized for a very long time but it is only in the past decade that these processes have been applied successfully to semiconductor materials.
Refractory metal silicon device technology. D. M. BROWN, W. E. ENGELER,~/I. GARFINKELand P. V. GRAY, Solid-St. Electron. 11 (1968), p. 1105. Films 2000-5000 A thick of Me or W deposited over thin films of thermally grown SiO 2 are shown to be effective high temperature diffusion masks against both phosphorus and boron. These metal films may be precisely patterned and their diffusion masking properties can be used to define the source and drain regions of MOSFETs. In this manner, selfregistered MOSFETs can be fabricated with a portion of the diffusion, masking metal film acting as the gate electrode. Using P or B doped deposited glasses as diffusion sources, n or p channel enhancement mode MOSFETs were made by diffusion through the exposed thin SiO 2 film intop and n type Si to form source and drain junctions. Contact was subsequently made by etching holes through the oxide layers to the source and drain regions and to the refractory metal gate electrode buried within the oxide layers. These devices exhibit channel mobilities between 200 and 300 cm ~ V-sec at gate voltages about 10 V above threshold. The stability of MOS structures processed in a similar manner has been measured. After being stressed at ± 6 × 105 V/cm and 250°C for 15 hr, these devices exhibited shifts in their C - V characteristics less than 200 mV. Measurement electronics for the three-polnt probe. P. A. SCHUMANN,JR., J. F. HALLENBACK,JR., M. R. POPONIAK and C. P. SCHNEIDER,Solid St. Technol., November (1968), p. 32. A review of the various techniques used to measure the breakdown voltage as determined by the three-point probe is presented. Descriptions are given of the a.c., d.c. pulse, and ramp systems with their variations. A new system involving a constant current ramp and electronic shut-off system is described and contrasted with previous techniques. The advantages and disadvantages of each system are described. Status of diffusion data in binary compound semiconductors. D. W. YARBROUGH,Solid St. Technol., November (1968), p. 23. A critical review of the literature is presented in an effort to establish the status of diffusion data in III-V compounds, II-VI compounds, and SiC. This report will be useful in providing a relatively complete review and bibliography of published diffusion data. Observed electrical behaviour for various impurities in binary compounds, the important temperature variation parameters for the diffusion coefficient, D o and E, and range of values for the diffusion coefficients of numerous species are tabulated. Those atomic species which produce anomalous concentration profiles in the binary semiconducting materials have been indicated. 4. THIN FILM CIRCUITS AND MATERIALS Tantalum films form reliable low cost circuits. D. R. TIBBETTS,Electron. Compon., May (1968), p. 551. In the case of the thin-film circuits described, all the resistors are made from a single film and adjustment needs to be carried out only where extreme accuracy is required. The film is deposited by a process of sputtering in vacuum which is inherently a very constant process. In fact, many people have failed to realize the true potentialities of sputtering because the degree of cleanliness in the sputtering system must approach that required for semiconductor processes. The same sputtering source can be made to give constant deposition conditions over a period of several months and all that is then required is a method of feeding substrates into the system one after the other. If the vacuum process is used solely to coat substrates with a continuous metal film in this way, a high throughput can be obtained and the cost of the vacuum stage is a negligible fraction of the overall cost. Hybrid thin film micro-electrouics--A quick and flexible method of micro-circuit construction. A. J. MARRIAGEand R. N. WHEATEN,Prec. I.R.E.E. Australia, May (1968), p. 137. Thin film integrated circuits can be made by depositing a pattern of resistive, dielectric and conductive materials on to an insulating substrate. The advantages and limitations of hybrid thin film micro-circuits are