- Email: [email protected]
An altered layer model for ion assisted deposition under net growth conditions
627
World Abstracts on Microelectronics and Reliability
stress and measurement polarity. We will discuss the differences in trap generation and charge trapping that occur during and after the high-voltage stressing of thin oxides.
wearout and breakdown. We will report here changes that have been observed in the I-V, l-t, and C - V characteristics of 10-nm-thick oxides on p-type substrates as a function of
8. T H I C K -
AND
THIN-FILM AND
COMPONENTS, MATERIALS
The growth and characterization of ZnSe epilayers grown by VPE and MOCVD. YAN-KUIN SU, CHUNG-CHENG CHANG and CHUNG-CHUANGWEI. Prog. Crystal Growth Charact. 17, 241 (1989). Zinc selenide (ZnSe) is a useful semiconductor for homojunction or heterojunction optoelectronic devices. In this paper we review the fabrication techniques of vapor-phase epitaxy (VPE) and metalorganic chemical vapor deposition (MOCVD) for the growth of ZnSe epilayers. These techniques can play important roles in achieving ZnSe blue-light-emitting devices. Recent and future trends in growing these devices are also reviewed and studied.
Pulsed laser deposition of barium titanate films on silicon. RASHMINAWATHEY,R. D. VISPUTE,S. M. CHAUDHARI,S. M. KANETKAR and S. B. OGALE. Solid-St. Commun. 71(1), 9 (1989). Barium titanate thin films have been deposited on single-crystal silicon by using pulsed ruby laser induced
ION
AND
CIRCUITS
vaporization from sintered bulk material. The dependence of the film properties on laser energy density, oxygen partial pressure during deposition and substrate bias has been investigated, and optimum conditions have been brought out for obtaining single-phase stoichiometric thin films. The films have been characterized by small angle X-ray diffraction (XRD), scanning electron microscopy (SEM) and spectroscopic ellipsometry.
Ion-implanted-induced structural modifications in Yt Ba2Cu30~-6 superconductor. S. N. YEDAVE,P. D. KODAU, S. T. BENDRE,R. VISWANATHAN,S. M. KANETKAR,S. M. CHAUDHARI and S. B. OGALE, Solid-St. Commun. 70(12), 1131 (1989). Ion-implantation-induced structural modifications in a Y~ Ba2CU~OT_~ superconductor are examined by a grazing angle X-ray diffraction technique. By using a range of grazing angles from 0.3 to 10°, it is shown that 100 keV Ar + implantation of the superconductor leads to amorphization as well as modification of grain size and orientation at dose values lower than 10~6ions cm-:. At the dose of 5 x 1016ions cm -2 the X-ray diffraction intensity is a factor of six less than for the original pellet, though the lines themselves are sharp. This shows coexistence of perovskite grains and amorphous matrix.
9. E L E C T R O N ,
HYBRID
LASER
Effect of argon implantation on antimony implanted silicon. G. S. VIRDI, S. K. CHATTOPADHYAYA, N. NATH and W. S. KnOKLE. Solid-St. Electron. 32(6), 433 (1989). In the present paper we submit the results on the effect of 50 keV argon ion-implantation on 100keV antimony implantation. Attempts have been made to measure impurity profiles of such samples using back-scattering and resistivity measurements following anodic oxidation plus a microetching technique, and to compare these results with the estimated values of range, straggling and sheet resistance on the basis of theory. Sheet resistance was measured using IC techniques. Argon implantation reduces the effective carrier concentration which in turn helps in increasing the value of sheet resistance and reducing channeling. New applications of focused ion beam technique to failure analysis and process monitoring of VLSI. K. NmAWA, K. NASU, M. MURASE,T. KAITO, T. ADACHIand S. INOUE. 27th a. Proc. IEEE/IRPS Int. Reliab. Phys. Syrup., 43 (1989). Two new applications have been developed: one is microscopic selective cross-sectioning and in situ obervation of the cross-section, and the other is the observation of aluminum microstructure. These applications make some failure analysis techniques simpler and less time-consuming. A new reliability problem associated with Ar ion sputter cleaning of interconnect vias. HIDEKI TOMIOKA, SHIN-ICHI TANABEand KOICHIROMIZUKAMI.27th a. Proc. IEEE/IRPS Int. Reliab. Phys. Syrup., 53 (1989). The cleanliness of a sputter-etched surface of an aluminum alloy in interconnect vias has been investigated. In situ Auger analysis of the
BEAM
TECHNIQUES
sputter-etched vias indicates that sputter-etch cleaning before metallization removed the natural oxide on the aluminum surface, but left a thin insulating layer due to redeposition of the atoms sputtered out of the intermetal dielectric. Existence of the redeposited layer was also confinned by SEM cross-sectional observation of the vias. The redeposited insulating layer was found to cause a new problem, resulting in contact failure of vias during a life test which included high-temperature storage and operation. A multi-pinhole contact model is proposed to explain the mechanism of the failure. An altered layer model for ion assisted deposition under oct growth conditions. G. CARTER,I. V. KATARDJIEV and M. J. NOaES. Vacuum 39(6), 571 (1989). A model for ion-assisted deposition under net growth conditions is proposed and analysed. Separate fluxes of depositing atoms and energetic ions are assumed, the role of the latter being to implant directly into the growing film structure, to intermix all atoms in the structure and. to sputter from the surface. A threelayer plus bulk substrate is assumed in which deposit and energetic atoms can trap in, be sputtered from and mixed inwards from an outer sputter layer. This second layer traps energetic atoms and receives atoms from and delivers atoms to the sputtering layer by atomic intermixing processes stimulated by the energetic particle flux. The third, deeper layer is where such processes have operated but subsequently terminated. The analysis reveals the importance of incident fluxes, stopping, mixing and sputtering processes in determining the different atomic constituent concentrations in these layers.
World Abstracts on Microelectronics and Reliability
stress and measurement polarity. We will discuss the differences in trap generation and charge trapping that occur during and after the high-voltage stressing of thin oxides.
wearout and breakdown. We will report here changes that have been observed in the I-V, l-t, and C - V characteristics of 10-nm-thick oxides on p-type substrates as a function of
8. T H I C K -
AND
THIN-FILM AND
COMPONENTS, MATERIALS
The growth and characterization of ZnSe epilayers grown by VPE and MOCVD. YAN-KUIN SU, CHUNG-CHENG CHANG and CHUNG-CHUANGWEI. Prog. Crystal Growth Charact. 17, 241 (1989). Zinc selenide (ZnSe) is a useful semiconductor for homojunction or heterojunction optoelectronic devices. In this paper we review the fabrication techniques of vapor-phase epitaxy (VPE) and metalorganic chemical vapor deposition (MOCVD) for the growth of ZnSe epilayers. These techniques can play important roles in achieving ZnSe blue-light-emitting devices. Recent and future trends in growing these devices are also reviewed and studied.
Pulsed laser deposition of barium titanate films on silicon. RASHMINAWATHEY,R. D. VISPUTE,S. M. CHAUDHARI,S. M. KANETKAR and S. B. OGALE. Solid-St. Commun. 71(1), 9 (1989). Barium titanate thin films have been deposited on single-crystal silicon by using pulsed ruby laser induced
ION
AND
CIRCUITS
vaporization from sintered bulk material. The dependence of the film properties on laser energy density, oxygen partial pressure during deposition and substrate bias has been investigated, and optimum conditions have been brought out for obtaining single-phase stoichiometric thin films. The films have been characterized by small angle X-ray diffraction (XRD), scanning electron microscopy (SEM) and spectroscopic ellipsometry.
Ion-implanted-induced structural modifications in Yt Ba2Cu30~-6 superconductor. S. N. YEDAVE,P. D. KODAU, S. T. BENDRE,R. VISWANATHAN,S. M. KANETKAR,S. M. CHAUDHARI and S. B. OGALE, Solid-St. Commun. 70(12), 1131 (1989). Ion-implantation-induced structural modifications in a Y~ Ba2CU~OT_~ superconductor are examined by a grazing angle X-ray diffraction technique. By using a range of grazing angles from 0.3 to 10°, it is shown that 100 keV Ar + implantation of the superconductor leads to amorphization as well as modification of grain size and orientation at dose values lower than 10~6ions cm-:. At the dose of 5 x 1016ions cm -2 the X-ray diffraction intensity is a factor of six less than for the original pellet, though the lines themselves are sharp. This shows coexistence of perovskite grains and amorphous matrix.
9. E L E C T R O N ,
HYBRID
LASER
Effect of argon implantation on antimony implanted silicon. G. S. VIRDI, S. K. CHATTOPADHYAYA, N. NATH and W. S. KnOKLE. Solid-St. Electron. 32(6), 433 (1989). In the present paper we submit the results on the effect of 50 keV argon ion-implantation on 100keV antimony implantation. Attempts have been made to measure impurity profiles of such samples using back-scattering and resistivity measurements following anodic oxidation plus a microetching technique, and to compare these results with the estimated values of range, straggling and sheet resistance on the basis of theory. Sheet resistance was measured using IC techniques. Argon implantation reduces the effective carrier concentration which in turn helps in increasing the value of sheet resistance and reducing channeling. New applications of focused ion beam technique to failure analysis and process monitoring of VLSI. K. NmAWA, K. NASU, M. MURASE,T. KAITO, T. ADACHIand S. INOUE. 27th a. Proc. IEEE/IRPS Int. Reliab. Phys. Syrup., 43 (1989). Two new applications have been developed: one is microscopic selective cross-sectioning and in situ obervation of the cross-section, and the other is the observation of aluminum microstructure. These applications make some failure analysis techniques simpler and less time-consuming. A new reliability problem associated with Ar ion sputter cleaning of interconnect vias. HIDEKI TOMIOKA, SHIN-ICHI TANABEand KOICHIROMIZUKAMI.27th a. Proc. IEEE/IRPS Int. Reliab. Phys. Syrup., 53 (1989). The cleanliness of a sputter-etched surface of an aluminum alloy in interconnect vias has been investigated. In situ Auger analysis of the
BEAM
TECHNIQUES
sputter-etched vias indicates that sputter-etch cleaning before metallization removed the natural oxide on the aluminum surface, but left a thin insulating layer due to redeposition of the atoms sputtered out of the intermetal dielectric. Existence of the redeposited layer was also confinned by SEM cross-sectional observation of the vias. The redeposited insulating layer was found to cause a new problem, resulting in contact failure of vias during a life test which included high-temperature storage and operation. A multi-pinhole contact model is proposed to explain the mechanism of the failure. An altered layer model for ion assisted deposition under oct growth conditions. G. CARTER,I. V. KATARDJIEV and M. J. NOaES. Vacuum 39(6), 571 (1989). A model for ion-assisted deposition under net growth conditions is proposed and analysed. Separate fluxes of depositing atoms and energetic ions are assumed, the role of the latter being to implant directly into the growing film structure, to intermix all atoms in the structure and. to sputter from the surface. A threelayer plus bulk substrate is assumed in which deposit and energetic atoms can trap in, be sputtered from and mixed inwards from an outer sputter layer. This second layer traps energetic atoms and receives atoms from and delivers atoms to the sputtering layer by atomic intermixing processes stimulated by the energetic particle flux. The third, deeper layer is where such processes have operated but subsequently terminated. The analysis reveals the importance of incident fluxes, stopping, mixing and sputtering processes in determining the different atomic constituent concentrations in these layers.