Showing papers on "Anodic bonding published in 1987"

A technology for high-performance single-crystal silicon-on-insulator transistors

Abstract: A process for forming transistors and circuits in a thin single-crystal silicon film on a glass substrate is presented. The process involves the electrostatic bonding of a silicon wafer to glass and the subsequent thinning of the wafer using doping-sensitive etchants to retain only the epitaxial layer. NMOS transistors have shown channel mobilities of 640 cm2/V-s, while leakage currents have been measured at less than 10-14A/µm.

Using a rapid thermal process for manufacturing a wafer bonded soi semiconductor

Abstract: A method of forming a high quality silicon on insulator semiconductor device using wafer bonding. The annealing time for the wafer bonding process is substantially reduced through the use of a rapid thermal annealer, thereby resulting in minimizing the redistribution of the doping concentration resulting from the annealing process.

Bonding sheet for electronic component and method of bonding electronic component using the same

Abstract: The bonding sheet (20) of the present invention comprises a substrate having an opening (22), and a low-melting point bonding metal (25) which closes the opening (22) or is arranged on the peripheral portion of the opening, to project in the opening. According to a bonding sheet (20) of the present invention, a low-melting point bonding metal (25) is interposed between a conductor pattern of a substrate (30) and electrode terminals (42) of an electronic component (40), and is bonded by thermocompression at a low temperature without melting the low-melting point bonding metal, so that bonding of a large number of electrode terminals can be completed by a single bonding operation.

Field‐assisted bonding below 200 °C using metal and glass thin‐film interlayers

Abstract: Bonding between similar or dissimilar surfaces with metal and glass thin‐film interlayers as well as bulk glass plates using an electric field assisted bonding technique at 160 °C or less is described. This low‐temperature field‐assisted bonding is achieved using, e.g., few μm thick glass films rf magnetron sputter deposited from Na or Li silicate glasses, and 0.05–1.0 μm thick Al, Sn, Mg, and Hf films. The bond strength thus achieved is found to be greater than the cohesive strength of the glass used. Results from x‐ray photoelectron spectroscopy analyses confirm the migration across the glass layer and the plating out on the cathode surfaces of mobile ions such as Na+ or Li+ during field‐assisted bonding. The migration and plating out of mobile ions can be detected in 10 s after the potential is applied and whether actual bonding between the metal and glass occurs or not. The possible bonding mechanism based on these XPS results is proposed.

Chemically strengthened glass article formed of float glass

Abstract: The invention relates to a method of strengthening a glass article formed of sheet glass produced by the float process. The strengthening method includes a known ion exchange treatment to replace alkali metal ions in the surface layers of the glass with, e.g., alkali metal ions larger in ionic radius such as potassium ions. To prevent warping of the glass article during the ion exchange treatment by the influence of a metal element such as tin used as the molten metal in the float process and diffused into one surface of the sheet glass, the glass article is pretreated by contacting at least said surface with an external source of sodium ions and/or lithium ions and heating the glass article together with the external source of the alkali metal ions at 350°-650° C. for 0.01-100 hr. The pretreatment is neither preceded nor followed by grinding or polishing of said surface of the glass. By incorporating the pretreatment, the ion exchange strenthening can be accomplished to a high degree without degrading flatness and surface smoothness of the glass even when the glass thickness is not more than about 3 mm.

Semiconductor device and production process thereof, as well as wire bonding device used therefor

Abstract: The present invention concerns a semiconductor device and a process for producing semiconductor device, as well as a wire bonding device used therefor. In accordance with the present invention, a ball formed at the top end of a bonding wire is sphericalized by electric discharge within a reducing gas atmosphere at a high temperature from 100° C. to 200° C. By using the ball of the bonding wire formed under such a condition to the bonding of the bonding pad of a semiconductor pellet, it is possible to conduct highly reliable ball bonding with excellent bondability and with no development of cracks or the like in the semiconductor pellet, as well as to obtain a highly reliable semiconductor device, that is, LSI or IC.

Soi by wafer bonding with spin-on glass as adhesive

Abstract: Two silicon wafers were bonded together with spin-on glass as the adhesive. Bonding strength depended heavily on the surface treatment. This was also confirmed by IR reflection measurement. A silicon-on-insulator (SOI) structure was achieved by thinning one of the wafers after the bonding. The resultant 5?m-thick SOI layer was stable at high temperatures and showed no degradation in its electrical characteristics.

Temperature stable optical bonding method and apparatus obtained thereby

Abstract: An optical element (10) is bonded to a support (12) by a resilient bonding agent (20). The bonding agent has the property of shrinking upon curing. It is placed within a bonding space (18) defined by rails (14, 16). Upon curing, the bonding agent shrinks and securely pulls the element against top surfaces (14a, 16a) of the rails under tension of the bonding agent.

Bonding silicon wafer to silicon nitride with spin-on glass as adhesive

Abstract: Using spin-on glass (SOG) as an adhesive, an Si wafer with thermal oxide was successfully bonded to one with an RF-sputtered Si3N4 film. This ensures that SOG films are effective in bonding Si wafers to less reactive surfaces than Si or SiO2 such as silicon nitride. It was also found that the previously reported bonding procedure can be simplified by suppressing the spin-induced radial striations of the SOG films.

Liquid-Phase Bonding of Silicon Nitride Ceramics

Abstract: Mg-Si-O-N glasses were used to bond dense Si3N4 ceramic pieces by a liquid-phase diffusion bonding mechanism. In this case, it was difficult to achieve defect-free bonding because, at low nitrogen content in the glass, a large mismatch in thermal expansion coefficient produced cracks perpendicular to the bonding glass layer. With an increase in nitrogen content, the glass layer became frothy and contained “bubbles.” However, when a small amount of elemental silicon was added to the glass, volatile reaction was suppressed and intimate bonding was achieved without thermal cracks.

Method of making a void free wafer via vacuum lamination

Abstract: A silicon wafer bonding technique is described utilizing low pressures and a dissolvable gas to substantially eliminate voids formed between the bonding surfaces of two wafers.

Flexible glass fiber mat bonding method

Abstract: A method of providing a unitary body comprised of two initially separate layers having similar coefficients of thermal expansion involves forming a mat of glass fibers in a configuration suitable for bonding the two layers together, placing the glass mat between them and heating the resulting stack to a temperature at which the individual fibers of the glass mat deform to form a continuous layer of glass which adheres to both layers, after which the stack is cooled to result in the unitary body.

Semiconductor-type pressure detector

Abstract: PURPOSE: To provide a firm bonding, excellence in durability and production at a low cost by stacking and using a glass suitable for anode bonding which was formed by sputtering as an intermediate material for the bonding of a semiconductor strain gauage chip with a metal diaphragm for pressure receiving. CONSTITUTION: On the bottom of a semiconductor strain gauge chip 2, a glass material 3 which is suitable for anode bonding and has a proper thermal expansion coefficient close to the thermal expansion coefficient of the chip is thinly stacked by sputtering as an intermediate material, and the semiconductor strain gauge chip 2 on which the thin glass material 3 was stacked is anode-bonded to the side of a metal diaphragm 11 opposed to a medium to be detected (diaphragm surface), which metal diaphragm has substantially similar thermal expansion coefficient to the semiconductor gauge chip and has a sufficient pressure resistance. With this, the glass thin film 3 has an appropriate thermal expansion coefficient value and the bonding strain and thermal stress involved in the bonding can be made small, so the semiconductor strain gauge chip 2 can be bonded to the metal diaphragm 11 firmly and positively, whereby the detection precision can be made high. COPYRIGHT: (C)1988,JPO&Japio

Silicon die bonding process

Abstract: A process for bonding silicon die (10) to a package. This process comprises the following steps: (a) providing to the back surface of the die (12) an adhesion layer (14) of material which exhibits superior adhesion to both the silicon die and a subsequently applied barrier layer (16); (b) providing to the adhesion layer (14) a barrier layer (16) which is impervious to silicon; (c) providing to the barrier layer (16) a bonding layer (18); and (d) bonding the die to the package by activating a binder composition disposed at the interface of the package and the bonding layer. The barrier layer prevents the migration of silicon to the bonding layer, both at the time of application of the bonding layer to the die and at the time of bonding the die to the package. The adhesion layer enhances the adhesion of the barrier layer material to the back surface of the die. Titanium is the preferred adhesion layer material while tungsten is the preferred barrier layer material. The bonding layer preferably comprises gold while the preferred binder composition is a gold-tin alloy solder. The enhanced adhesion of the barrier layer which prevents silicon migration into the gold produces highly reliable bonds. In another embodiment, a stress relief layer is interposed between the adhesion layer and the back of the silicon die. The material of the stress relief layer is alloyed to the silicon at the back surface of the die which relieves stresses in the die and enhances the planarity of the back surface. This produces bonds which exhibit superior electrical and thermal contact characteristics.

Stress relief substrate metallization

Abstract: A technique for metallizing a substrate while providing stress relief for the metallization on the substrate is disclosed. Chrome conductive metallization (22) is deposited on a top surface (21) of an insulating glass substrate (20). An interior gold conductive metallization (23) is deposited on the chrome, and metallization (24) having a substantial nickel composition is deposited on the gold. Subsequently, an additional outer gold metallization (25) is provided on the nickel, and solder is provided on the additional gold metallization. Prior to the application of solder to the outer gold layer 25, the metallization layers are subjected to anodic bonding temperatures and voltage potentials. The gold layer between the nickel and chrome layers diffuses along the grain boundaries of the nickel and chrome layers, thus reducing the ability to transmit stress through these metallizations induced by the solder. The present metallization structure prevents solder-induced stress from rupturing either the bond between the chrome layer and glass substrate or the glass substrate. This allows application of a relatively thick layer of chrome to glass sufficient such that chrome can be deposited in feedthrough holes (31, 32) in the glass. Preferably, such a metallization technique is utilized for manufacturing a silicon capacitive pressure sensor (30).

Binary strip bonding

Abstract: An improved method of chemical bonding wherein a bonding polymer and its corresponding curing agent are deposited on plastic strips with adhesive backings. When bonding is desired, then these strips are applied to the bondable structural surfaces and the exposed deposits are brought together through agitation, mixing the two components and initiating the bonding action.

Process for producing bonded joints by means of a laser

Abstract: The invention relates to a process for temperature-controlled laser bonding, for example chip bonding and die bonding with hot-melt adhesives, in which the semiconductor chips before individual separation, i.e the wafer, is thinly coated with resistant hot-melt adhesive which is hard at room temperature, the individual chips are positioned with an automatic component mounting installation (epoxy die bonder) and in the following cycle are bonded "on-line" with a temperature-controlled Nd:YAG laser via glass fibre cables. Furthermore, the quick bonding or curing of large-area lightweight structures by means of laser spot bonding or seam bonding is described. The process is explained with reference to exemplary embodiments and its advantageousness is demonstrated by diagrams in the drawing.

Method for forming cellular film

Abstract: PURPOSE:To obtain a cellular glass film having sufficient joining force and homogeneous pores, by forming a glass layer capable of separating a phase through a glass layer without separating the phase by heat treatment on a ceramic substrate surface and subjecting the resultant substrate to heat and acid treatment. CONSTITUTION:A glass layer without separating a phase by heat treatment is formed on a ceramic substrate surface to improve glass adhesivity of the substrate surface to glass. A glass layer capable of separating a phase by heat treatment is then formed on the above-mentioned substrate surface to carry out heat treatment and then acid treatment to provide a cellular glass layer. An oxide based ceramic, such as steatite or alumina, and nonoxide based ceramic, such as silicon carbide or silicon nitride, are cited as the ceramic substrate used. Glass, such as borosilicate based or lead based glass, is cited as the glass without separating the phase by heat treatment. Glass, such as R2O-B2O2-SiO2 based or R2O-B2O2-ZrO2 based glass, is cited as the glass capable of separating the phase by heat treatment.

Diffusion bonding SiC or Si3N4 to Nimonic 80A

Abstract: A method of diffusion bonding SiC or Si3N4 to Nimonic 80A was developed to establish the fundamental technology for the application of ceramics to machinery components used at elevated temperature. An analysis of the thermal stress that occurs in ceramic/Nimonic 80A bonded composites was done using the finite element method, and a bonding experiment based on the analytical results was conducted. The composites were produced by the insert metal bonding method, using varying thickness of Ni, W, Kovar, Cu and so on. It was found that the residual thermal stress in the ceramic part of the composite was extremely low and that the composite had a tensile strength of more than 98 MPa at room temprature. Furthermore, the paper describes the feasibility of the application ofthis bonding method to components for marine diesel engines.

Anodic bonding method

Abstract: PURPOSE:To eliminate voids in a part to be finally obtained by anodic bonding by separating in advance at least one SiO2 by grooves into a plurality of insular parts CONSTITUTION:A plurality of insular SiO2 7 separated by grooves 6 are formed by patterning on one Si substrate 5, the surfaces of SiO2 7 and SiO2 3 are opposed to be bonded in this state When temperature is raised in a furnace, the surface of the SiO2 7 is started to be bonded at the side of the substrate 5, so that voids resulted from bonding at multiple points are concentrated in the groove 6 Thus, when the grooves formed by the voids are thereafter removed, a small substrate having a bonded part without void can be obtained

Bonding of silicon to silicon by solid‐phase epitaxy

Abstract: Using concepts of solid‐phase epitaxy, a sealed and structurally sound bond between two silicon wafers has been achieved with aluminum, platinum silicide, or germanium as the transport medium. Only in the case of aluminum did microprobe analysis show an interface clear of the bonding medium. The bond quality was tested by bonding wafers of different crystal orientation and then intentionally cleaving and fracturing the bonded wafers. A clean fracture was obtained without the wafers falling apart. Leak test of sealed cavities suggests that a hermetically sealed enclosure can be achieved with this technique.

Ion electrode and method of making it

Abstract: A liquid junction electrode 10 formed from a silicon body 14 and having a glass membrane 22 attached thereto. A reference electrode is constructed by forming the glass membrane 22 from porous glass having a preferable pore size in the range of 40 angstroms to 75 angstroms. The porous glass membrane 22 has a coating 24 of glass containing mobile ions that is electrostatically bonded to the silicon body 14. Alternatively, a glass plug 92 is formed from a paste of ground glass and organic binder that is heated to cause formation of pores and bonding of the glass plug 92 to a silicon body 94. An ion-sensitive electrode is constructed by forming the membrane 52 from an ion-sensitive glass or by filling the pores of the porous glass membrane 22 with an ion-sensitive material.

Silicon and Silicon Dioxide Thermal Bonding

Abstract: The quality of the bond produced after mating oxidized and/or unoxidized silicon wafers has been studied using acoustic microscopy, infrared transmission thermographs, and transmission electron microscopy. The acoustic microscopy revealed that a significant number of unbonded regions (gaps) remain at the bond interface after bonding in oxygen, nitrogen, or high vacuum, and then annealing. These gaps could be virtually eliminated by a subsequent hyperbaric annealing step. The thermal imaging was found to have insufficient resolution to give a detailed picture of the bond quality. Transmission electron microscopy showed that an excellent bond could be produced when bonding clean silicon wafers, with only very small oxide or void bubbles present at the interface. Bonding two oxidized wafers resulted in a buried oxide layer with no detectable bond line. Mating an oxidized wafer to an unoxidized wafer produced a bonded silicon/oxide interface which was nearly indistiguishable from the wafer/thermal oxide interface.

Wire Bonding to GaAs Electronic Devices

Abstract: GaAs electronic devices are becoming increasingly used in the microelectronics industry especially in solid state microwave, ultra high speed digital processing and optoelectronic applications. However, in the manufacture of the GaAs devices, problems due to the inherent brittleness of the GaAs and batch to batch variability of the bond pad metallisation have commonly been experienced. This has resulted in some difficulties in wire bonding to GaAs devices with ultrasonic and thermocompression wire bonding techniques. This paper describes a programme undertaken to investigate Au wire bonding techniques to GaAs devices. Specifically, bonding trials have been performed on a range of GaAs substrates using pulse tip and continuously heated thermocompression bonding and ultrasonic bonding. The results of this work have shown that thermocompression and ultrasonic wire bonding techniques are cabable of producing acceptable bonds to GaAs devices, although some of the advantages and limitations of each technique have been demonstrated. Thermocompression bonding with a continuously heated capillary gave the most tolerant envelope of bonding conditions and highest bond strengths. Pulse tip thermocompression bonding gave a less tolerant envelope of acceptable bonding conditions, required a longer bonding time and the wire was weakened above the ball bond. Ultrasonic bonding did not require any substrate heating to give acceptable bonds. However, the choice of equipment can be critical if damage to the device is to be avoided.

A method of treating glass surfaces with coupling agents and resins to provide an improved surface for bonding a final resin

Abstract: Use of synthetic resins with glass and glass fibers to produce composite glass structures. In particular, the present invention provides a method for coating glass surfaces with a combination of a reinforcement resin and a coupling agent to produce composites which resist electrical, chemical and mechanical stresses before the incorporation of a final resin. These final coated glass fibers exhibit enhanced stability and resistance to electrical, chemical and mechanical stresses and can be layered and pressed into glass laminate products.

Dissolution and Disintegration of Uniform SiO2 Layers During Direct Silicon Wafer Bonding

Abstract: The conditions for the dissolution and disintegration of SiO2 layers between silicon wafers during direct wafer bonding are discussed in terms of two possible mechanisms. The calculated maximal thickness of a SiO2 layer which may be completely dissolved does not only depend on the bonding temperature and time but also on the starting concentration of interstitial oxygen in the silicon wafers. Finally, the influence of rotational misorientation of the two wafers on the behavior of the S1O2 layers is dealt with.

Silicide to silicon bond

Abstract: A bonding layer comprising amorphous silicon, titanium, chromium, or tungsten, is used between the silicide and the N+ polysilicon layer. The bonding layer is preferably less than 50 nm. thick. After the bonding layer is deposited, a silicide layer is deposited and the wafer is then sintered at 900-1000°C for ten minutes or less.