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Gold-to-gold TAB ILB with a laser
454
World abstracts on microelectronics and reliability
SiC thin film was sputtered on a Si substrate at 600°C and annealed at 1300°C for 5 h in Ar atmosphere. For this MOSFET, the current-voltage characteristics of 1.6 and 0.6 #m channel length have been investigated. In this structure, the drain characteristics show an incomplete saturation because the channel depth is too wide to be depleted. For the other MOSFET, the SiC thin film is deposited at the sidewall of the SiOz insulator by RF sputtering at 600~C, and a 0.41am channel length has been developed. This M O S F E T shows good saturation characteristics. Also, this device possesses a drain breakdown voltage beyond 16 V. These experimental results give the foundation for the future development of submicron SiC power integrated circuit technology. Performance of thin-film chip resistors. LARRY BOS. IEEE Transactions on Components, Packaging, and Manufacturing Technology--Part A, 17, 3, 359 (September 1994). Increased use of thin-film surface mount chip resistors in military and high-performance industrial equipment has led to an increased awareness of potential failure modes in harsh environments. In this work, we have studied the behavior of chip resistors fabricated from tantalum nitride and nichrome metal films under biased humidity and have measured widely different results attributable to the metal film and protective system. The effects of electrostatic discharge (ESD) and high-temperature stability on these small resistive devices was also examined and related to the resistor design. Effect of inorganic binders on the properties of thick film copper conductor. Tosmo OGAWA et al., IEEE Transactions on Components, Packaging, and Manufacturing Technology Part A, 17, 4, 625 (December 1994). Adhesion strength and solderability of a copper thick film on alumina substrate were studied. Films were prepared with three kinds of inorganic binders, i.e., glass flits, mixture of glass flits and metal oxides, and metal oxides. The effects of inorganic binders on the adhesion and solderability were examined by analyzing physical and chemical behavior of the inorganic binders in the copper thick film during firing. The films with an addition of glass flit or mixtures of glass frit and metal oxide did not provide good adhesion and solderability simultaneously. However, the copper thick film containing 10wt°J~, bismuth oxide had excellent characteristics, i.e., high adhesion strength, good solderability, and low sheet resistivity. 9. ELECTRON, ION AND LASER BEAM TECHNIQUES Metal capping of MCM thin film features using a laser. R. S. PATEL,T. A. WASS1CKand C. Y. RALSTON.IEEE Transactions on Components, Packaging, and Manufacturing Technology--Part B, 17, 3, 264 (August 1994). A laser process to provide a thin barrier or
capping metal over the copper features of a multichip module thin film (MCM-D) structure is described. Capping of copper features is required to avoid copper corrosion and diffusion into overlaying dielectric layers of thin film structure. Furthermore, in a multi-level thin film structure, certain barrier metals provide improved adhesion for the subsequent dielectric layer. Experiments with XeCI and Nd-Yag lasers were performed to determine the best laser source for a copper/polymer/ceramic material set. The laser capping process is more robust and quicker than conventional photolithography or electroless plating capping processes, while eliminating the wet chemical operations. Also, the laser capping process eliminates the undercapping and variable capping metal thickness problems associated with photolithography and/or electroless plating techniques. The results of capping metal features on bare glass ceramic and polymer surfaces are described. Gold-to-gold TAB ILB with a laser. PHIL SPLETTER. IEEE Transactions on Components, Packaging, and Manufacturing Technology--Part B, 17, 4, 554 (November 1994). A new method for bonding gold plated TAB leads to gold bumps is presented. This method uses a frequency doubled N d : Y A G laser which provides energy in both the visible (0.533 lam) and near IR (1.064 ~tm) spectra. This combination of wavelengths overcomes the difficulty of bonding gold with only 1.064 ~tm radiation where 98% of the radiation is reflected. In the method presented in this paper, 0.5334tm radiation, of which 25-50% is absorbed by gold, is used to heat the gold which becomes more absorptive to the 1.0644tm radiation that is used to form the bond. Bonding experiments were conducted and samples were exposed to environmental testing. While there were initial bond failures, 85~o of the bonds did not degrade during environmental exposure indicating the potential for the process. Mass production of laser diodes by MBE. HIROSHI MATAKI and HARUO TANAKA. Microelectronics Journal, 25, 619 (1994). Molecular beam epitaxy (MBE) plays an important role in the mass production of A1GaAs laser diodes which have been widely used in a variety of opto-electronic applications. This paper provides an overview of self-aligned structure AIGaAs laser diodes fabricated by MBE ('SAM laser diodes') focusing on the GaAs passivation technique that we put into practical use for the first time, and on the modification of conventional MBE systems. Several features of SAM laser diodes for practical applications are also reviewed. Selection of IR detectors for a fast laser soldering process with simultaneous solder joint qualification. JOHANN NICOLICS, DIETER SCHROTTMAYER and LASZLO MUSIEJOVSKY. IEEE Transactions on Components, Packaging, and Manufacturing Technology-Part B, 17, 4, 596 (November 1994). High effort is
World abstracts on microelectronics and reliability
SiC thin film was sputtered on a Si substrate at 600°C and annealed at 1300°C for 5 h in Ar atmosphere. For this MOSFET, the current-voltage characteristics of 1.6 and 0.6 #m channel length have been investigated. In this structure, the drain characteristics show an incomplete saturation because the channel depth is too wide to be depleted. For the other MOSFET, the SiC thin film is deposited at the sidewall of the SiOz insulator by RF sputtering at 600~C, and a 0.41am channel length has been developed. This M O S F E T shows good saturation characteristics. Also, this device possesses a drain breakdown voltage beyond 16 V. These experimental results give the foundation for the future development of submicron SiC power integrated circuit technology. Performance of thin-film chip resistors. LARRY BOS. IEEE Transactions on Components, Packaging, and Manufacturing Technology--Part A, 17, 3, 359 (September 1994). Increased use of thin-film surface mount chip resistors in military and high-performance industrial equipment has led to an increased awareness of potential failure modes in harsh environments. In this work, we have studied the behavior of chip resistors fabricated from tantalum nitride and nichrome metal films under biased humidity and have measured widely different results attributable to the metal film and protective system. The effects of electrostatic discharge (ESD) and high-temperature stability on these small resistive devices was also examined and related to the resistor design. Effect of inorganic binders on the properties of thick film copper conductor. Tosmo OGAWA et al., IEEE Transactions on Components, Packaging, and Manufacturing Technology Part A, 17, 4, 625 (December 1994). Adhesion strength and solderability of a copper thick film on alumina substrate were studied. Films were prepared with three kinds of inorganic binders, i.e., glass flits, mixture of glass flits and metal oxides, and metal oxides. The effects of inorganic binders on the adhesion and solderability were examined by analyzing physical and chemical behavior of the inorganic binders in the copper thick film during firing. The films with an addition of glass flit or mixtures of glass frit and metal oxide did not provide good adhesion and solderability simultaneously. However, the copper thick film containing 10wt°J~, bismuth oxide had excellent characteristics, i.e., high adhesion strength, good solderability, and low sheet resistivity. 9. ELECTRON, ION AND LASER BEAM TECHNIQUES Metal capping of MCM thin film features using a laser. R. S. PATEL,T. A. WASS1CKand C. Y. RALSTON.IEEE Transactions on Components, Packaging, and Manufacturing Technology--Part B, 17, 3, 264 (August 1994). A laser process to provide a thin barrier or
capping metal over the copper features of a multichip module thin film (MCM-D) structure is described. Capping of copper features is required to avoid copper corrosion and diffusion into overlaying dielectric layers of thin film structure. Furthermore, in a multi-level thin film structure, certain barrier metals provide improved adhesion for the subsequent dielectric layer. Experiments with XeCI and Nd-Yag lasers were performed to determine the best laser source for a copper/polymer/ceramic material set. The laser capping process is more robust and quicker than conventional photolithography or electroless plating capping processes, while eliminating the wet chemical operations. Also, the laser capping process eliminates the undercapping and variable capping metal thickness problems associated with photolithography and/or electroless plating techniques. The results of capping metal features on bare glass ceramic and polymer surfaces are described. Gold-to-gold TAB ILB with a laser. PHIL SPLETTER. IEEE Transactions on Components, Packaging, and Manufacturing Technology--Part B, 17, 4, 554 (November 1994). A new method for bonding gold plated TAB leads to gold bumps is presented. This method uses a frequency doubled N d : Y A G laser which provides energy in both the visible (0.533 lam) and near IR (1.064 ~tm) spectra. This combination of wavelengths overcomes the difficulty of bonding gold with only 1.064 ~tm radiation where 98% of the radiation is reflected. In the method presented in this paper, 0.5334tm radiation, of which 25-50% is absorbed by gold, is used to heat the gold which becomes more absorptive to the 1.0644tm radiation that is used to form the bond. Bonding experiments were conducted and samples were exposed to environmental testing. While there were initial bond failures, 85~o of the bonds did not degrade during environmental exposure indicating the potential for the process. Mass production of laser diodes by MBE. HIROSHI MATAKI and HARUO TANAKA. Microelectronics Journal, 25, 619 (1994). Molecular beam epitaxy (MBE) plays an important role in the mass production of A1GaAs laser diodes which have been widely used in a variety of opto-electronic applications. This paper provides an overview of self-aligned structure AIGaAs laser diodes fabricated by MBE ('SAM laser diodes') focusing on the GaAs passivation technique that we put into practical use for the first time, and on the modification of conventional MBE systems. Several features of SAM laser diodes for practical applications are also reviewed. Selection of IR detectors for a fast laser soldering process with simultaneous solder joint qualification. JOHANN NICOLICS, DIETER SCHROTTMAYER and LASZLO MUSIEJOVSKY. IEEE Transactions on Components, Packaging, and Manufacturing Technology-Part B, 17, 4, 596 (November 1994). High effort is