Showing papers on "Silicon nitride published in 1972"

Semiconductor structure having metallization inlaid in insulating layers and method for making same

Abstract: In a semiconductor structure with multiple levels of metallization on the surface, each metallization pattern is inlaid in trenches formed in an insulating layer. The surface of the metallization is flush with or somewhat lower than the surface of its associated insulating layer. In a preferred embodiment, the different etching characteristics of glass and silicon nitride are utilized to form the trenches in the glass layer. The glass comprises the insulating layer and the nitride forms the bottom of the trench.

Process of producing semiconductor devices

Abstract: By etching away a silicon nitride coating on a semiconductor substrate by photolithographic technique, windows of a predetermined pattern are formed in the coating to serve to deposit electrodes on and diffuse active regions into the substrate. Then a silicon dioxide coating deposited on the nitride coating and within the windows and partly removed by photolithographic technique to again form the windows for diffusion followed by the diffusion of the active regions into the substrate. An etchant chiefly attacking the oxide coating is used to again make all the windows for depositing the electrodes within them on the substrate.

Hot pressed silicon nitride

Abstract: A hot pressed silicon nitride product is described, the product having high strength at room temperature as well as high strength at elevated temperature. The product has a flexural strength in excess of 100,000 psi at 20*C., in excess of 90,000 psi at 1,200*C., in excess of 35,000 psi at 1,375*C, and preferably above 45,000 psi at 1,375*C. A preferred form of the product includes between .25 and 2.0 mg in the form of complex silicate, which silicate also contains a limited amount of iron, aluminum and calcium. The complex silicate has a liquidus above 1,400*C. The product has a density between 3.1 and 3.3 g/cc, the total oxygen content of the product being less than 5%.

Method for producing ceramics of silicon nitride

Abstract: A method for producing silicon nitride base ceramics products having high heat resistance, high abrasion resistance and low thermal expansion from the mixed powders of silicon nitride and alumina or from the mixed powders of silicon nitride, alumina and aluminum nitride. The method includes heating said mixed powders at a temperature between 1650 DEG and 2000 DEG C under a high pressure or no pressure. During the heating most of the alumina and aluminum nitride are occluded in silicon nitride and said silicon nitride base ceramics products are formed.

Production of silicon nitride material components

Abstract: SILICON NITRIDE COMPONENTS ARE FORMED BY HOT MILLING AND THEN SHAPING A DOUGH-LIKE MATERIAL COMPRISING SILICON POWDER AND A SUITABLE ORGANIC CHEMICAL BINDER CONSISTING OF FROM 35 TO 40% BUTYL METHACRYLATE AND 60-65% TRICHLOROETHYLENE AND SUBSEQUENTLY SUBJECTING THE FORM TO A NITRIDING TREATMENT.

A METHOD OF VAPOR DEPOSITING A LAYER OF Si N ON A SILICON BASE

Abstract: The present invention relates to dielectric coatings for electronic devices such as rectifiers, transistors and capacitors. More specifically, the invention relates to dielectric coatings comprising silicon nitride films alone or in combination with silicon dioxide films, and to methods for the production of silicon nitride coatings by reacting silane, silicon halides or halosilanes with ammonia.

Method of joining a pair of silicon nitride parts

Abstract: To join a pair of silicon nitride parts, a powdered glass consisting of silica, alumina and an alkaline earth metal oxide is provided on at least one of the parts to be joined. The powdered glass is then heated so as to produce molten glass between the parts whereby, on cooling, the glass provides a joint between the parts.

Solid diffusion sources containing phosphorus and silicon

Abstract: 1. A SOLID PHOSPHORUS CONTAINING SOURCE BODY FOR SEMICONDUCTOR DIFFUSION DOPING TREATMENT, SAID BODY COMPRISING ABOUT 5 TO ABOUT 70 WT. PERCENT OF COMPOUNDS OF PHOSPHORUS AND SILICON AND THE BALANCE SILICON CONTAINING ADDITIVES, WHEREIN THE COMPOUNDS OF PHOSPHORUS AND SILICON ARE SELECTED FROM THE GROUP CONSISTING OF COMPOSITIONS OF SIO2. P2O5, 2SIO2.P2O5, AND SIO2.2PO5, AND THE SILICON CONTAINING ADDITIVES ARE SELECTED FROM THE GROUP CONSISTING OF SILICON NITRIDE, SILICON OXIDE AND SILICON METAL.

Coated semiconductor structures and methods of forming protective coverings on such structures

Abstract: A semiconductor structure with a metallic oxide coated surface, a silicon nitride coating on the metal oxide and a covering coating of glass over the coated surface.

Processes for the localized and deep diffusion of gallium into silicon

Abstract: Process for the localized and deep diffusion of gallium into silicon, and silicon nitride mask utilization; and semi-conductor devices obtained thereby. A process of this type comprises the following operations: a) preparation of the surface of a specimen of N-type silicon intended to receive the diffusion localization mask; b) deposition of a first oxide layer on this surface; c) deposition of a silicon nitride layer forming a mask on the first oxide layer; d) photoengraving of the mask by means of a photosensitive product and a transfer layer formed by a second oxide layer; and opening of windows of localized diffusion in the mask; e) prediffusion of gallium into the silicon by means of the windows, and through the first oxide layer; f) removal of the silicon nitride mask and of the first oxide layer; g) deposition of a new first oxide layer on the whole silicon surface, followed by a new silicon nitride layer on this oxide layer; h) thermal treatment for penetration diffusion of the gallium into the silicon; i) removal of the layer of oxide and silicon nitride deposited during operation g), in order to obtain a structure with a localized and deep P-N junction. The invention makes it possible, in particular, to obtain new combinations of structures having localized zones of diffused gallium, diodes or thyratrons having localized P-N junctions, with a silicon nitride mask whose use can reduce the contamination of the semi-conductor material by oxygen.

Apparatus for the gettering of semiconductors

Abstract: A process for the gettering of semi-conductors wherein the semi-conductors are placed between and in contact with solid bodies selected from the group consisting of quartz glass, silicon nitride and boron nitride which are then heated to a gettering temperature preferably between 1,000 DEG C and 1,200 DEG C. The heating is preferably carried out under a vacuum or in the presence of an inert atmosphere. When boron nitride is used for the solid bodies, the process can serve simultaneously for also producing the desired doping characteristic within the semi-conductor.

Porous metal insulator sandwich membrane

Abstract: A membrane for use in reverse osmosis and electrodialysis separation processes comprising a thin metal layer with a thin layer of insulator material on each side thereof, the membrane being porous with the pores having uniform radii from 5 angstroms and lower to approximately 100 angstroms, and means associated with the metal layer for controlling the surface charge density by external electrical circuitry whereby ionic transfer through the pores is controlled. The membrane is made by (a) depositing sequentially by radio-frequency sputtering technique 5-500 angstrom layers of platinum and silicon nitride on a 50-100 micron thick glass substrate to form a thin sandwich. Then (b) there are chemically etched 300 micron diameter holes in the glass substrate by using a mask of sputter-etched molybdenum metal with a thin molybdenum layer functioning as a stopping layer for the etching step. Next (c) the molybdenum masking layer is removed and, using the 300 micron holes in the substrate as a pattern, the molybdenum stopping layer is chemically etched through. Next (d) the resulting sandwich structure is irradiated with fission fragments to produce damage tracks in the Si3N4 layers, after which these layers are chemically etched along the fission fragment damage tracks. Finally (e) the metal membrane layer is chemically etched through, using the small holes in the surrounding Si3N4 dielectric layers as a mask.

Silicon nitride-nickel compatibility: the effects of environment

Abstract: The effect of gaseous environment on the high temperature stability of nickel-coated silicon nitride whiskers has been investigated. Under vacuum conditions above 900°C, the nickel coatings broke up to form spheroidal particles, which subsequently became faceted (activation energy = 26 kcal/mol) and wetted the whiskers (activation energy=74 kcal/mol) In addition, at 1100° C, whisker disintegration occurred rapidly due to the formation of a nickel suicide reaction product. Under similar conditions in a nitrogen atmosphere the whiskers remained coherent and in an argon atmosphere the whiskers developed side growths. These results are correlated with variations in the nitrogen and oxygen partial pressures between the various conditions.

Manufacture of silicon nitride powder

Abstract: A method of manufacturing a silicon nitride powder comprises heating a bed of silicon powder in a furnace having an atmosphere containing nitrogen so that the silicon reacts with the nitrogen to produce silicon nitride. The exothermic reaction between the silicon and the nitrogen is monitored, either by comparing the temperature in the reaction bed with the temperature at another point in the furnace, or by allowing the nitrogen containing atmosphere to flow through the furnace and measuring the rates of flow of the atmosphere into and out of the furnace. The partial pressure of the nitrogen in the furnace atmosphere is then controlled in accordance with the exothermic reaction so as to ensure that the temperature in the bed does not exceed a predetermined value above which β-phase silicon nitride is formed, the partial pressure of the nitrogen in the furnace being controlled by effecting at least one of the steps of: A. diluting the nitrogen in the furnace atmosphere and, B. evacuating the furnace.

Electronic Processes in Metal-Silicon Nitride-Silicon Dioxide-Silicon Systems

Abstract: The electronic properties of MNOS diodes consisting of vapor deposited Si3N4 and thermally grown SiO2 films are studied. The diodes exhibiting injection or ion drift type hysteresis are prepared using n- or p-type substrate. It is found that ion drift type MNOS diodes utilizing n-type substrate exhibits a new type of C-V and I-V characteristics, while the other kinds of diodes exhibit similar characteristics as those of MNS diodes. This new type of characteristics are interpreted in terms of single carrier (electron) transport while the other ones are interpreted in terms of electron and hole transport throughout the diodes. Combining these findings with the general concept of charge transport and storage (CTS) model, a two carrier CTS model which gives a qualitative but unified understanding of shift characteristics of flat band voltage as well as C-V and I-V curves associated with MNOS diodes is proposed.

A High Production System for the Deposition of Silicon Nitride

Abstract: Amorphous silicon nitride is well known as a barrier to the penetration of alkali metal contaminants into junctions of semiconductor devices and as a gate dielectric for MIS devices. This paper discusses the operating characteristics of a production system for the deposition of silicon nitride by the ammonolysis of silicon tetrachloride in a hot wall furnace, and the characteristics of the resulting films.The protective film (1700–2500Aa) for bipolar devices can be deposited at a rate of 120 wafers/hr. For MIS work, where film thickness directly affects device threshold voltage, better uniformity can be achieved by modifying the wafer placement and operating procedures. The nitride films are amorphous with an index of refraction of approximately 1.95; the surface‐state density is in the order of 1012; and the etch rate in buffered hydrofluoric acid is .

Device Degrdation from the Effects of Nuclear Radiation on Passivation Materials

Abstract: Devices that utilized three different commercial passivation processes were studied in a nuclear radiation environment to determine if the passivation process influences the radiation tolerance of the device Comparisons were made between devices obtained from the same manufacturer The passivation processes studied featured silicon dixoide, silicon nitride and aluminum oxide Irradiations were performed with the devices in both a biased and unbiased mode The results show that the device with silicon dioxide passivation degraded the most The nitride devices having beam leads showed no saturation of the induced degradation while the other processes did for a dose of 1 × 107 (Si) All devices studied showed a small bias dependence The addition of an aluminum oxide or silicon nitride passivation layer (over the silicon dioxide surface) for an increased reliability definitely induces no increased radiation degradation

Backscattering Studies of Anodization of Aluminum Oxide and Silicon Nitride on Silicon

Abstract: Anodic oxidation of amorphous and polycrystalline aluminum oxides and amorphous silicon nitride deposited by chemical reactions on silicon were investigated by use of 2 MeV 4He + ion backscattering spectra and optical microscope examination. In anodization, the oxide layer was formed underneath the original aluminum oxide film and on the top surface of the silicon nitride layer. For a fixed current, the anodic voltage characteristics for aluminum oxide exhibited breakdown effects. After breakdown the aluminum oxide became nonuniform, and was removed at later stages of anodization, leaving a silicon oxide layer. For 700°C‐grown aluminum oxide, irregular surfaces were formed after all stages of anodization while for 830°C‐grown aluminum oxide, the oxide layer formed at later stages was similar in thickness and uniformity to those of anodically grown silicon oxide layers on bare silicon. The anodic voltage characteristics for silicon nitride did not exhibit breakdown. Backscattering data showed linear dependences on anodizing time of the decrease in amount of nitrogen and increase in amount of oxygen, suggesting that the nitrogen was replaced by oxygen during anodization. A similar mechanism was proposed by Schmidt and Wonsidler, and by Tripp.

The combination of silicon nitride and aluminum anodization for semiconductor device passivation

Abstract: The combination of silicon nitride and barrier anodization of the aluminum interconnects serves as excellent passivation for bipolar silicon devices, even under conditions of massive ionic contamination at temperatures as high as 400°C. This combination removes the restriction that silicon nitride positively overlap the edges of all contact cuts and thus results in savings in device area. In addition, the processing complexity is somewhat reduced in that the silicon nitride can be delineated by a self-aligning anodization technique.

Process for the formation of selfaligned silicon and aluminum gates

Abstract: A PROCESS FOR THE SIMULTANEOUS FORMATION OF SELFALIGNED SILICON GATES AND ALUMINUM GATES HAVING SELFALIGNED CHANNEL REGIONS ON THE SAME WAFER IS DISCLOSED. BASICALLY, THE PROCESS CONSISTS OF THE DEPOSITION OF SUCCESSIVE LAYERS OF SILICON NITRIDE AND POLYCRYSTALLINE SILICON OVER THICK AND THIN SILICON DIOXIDE REGIONS WHICH ARE DISPOSED ON THE SURFACE OF A SEMICONDUCTOR WAFER. POLYSILICON GATES ARE DELINEATED IN THE THIN OXIDE REGIONS. SUBSEQUENTLY, A CHEMICALLY VAPOR DEPOSITED SILICON DIOXIDE LAYER IS FORMED OVER THE SURFACE OF THE EXPOSED SILICON NITRIDE LAYER AND OVER THE POLYCRYSTALLINE SILICON GATE GEGIONS. AT THIS POINT, THE CVD OXIDE IS DELINEATED TO FORM AN OXIDE MASK WHICH WILL PERMIT THE REMOVAL OF SILICON NITRIDE DOWN TO THE THIN OXIDE AT CERTAIN REGIONS WHERE DIFFUSION WINDOWS ARE TO BE FORMED IN EXPOSED THIN OXIDE REGIONS WHICH ARE SUBSEQUENTLY REMOVED BY A DIP ETCH. WHILE THE EXPOSED THIN OXIDE REGIONS ARE MASKED BY EITHER SILICON NITRIDE PORTIONS OR POLYCRYSTALLINE SILICON GATE REGIONS, THE MASKING REGIONS OF CVD OXIDE WHICH PROTECTED THE SILICON NITRIDE LAYER ARE SIMULTANEOUSLY REMOVED BY THE DIP ETCH WHICH OPENS THE DIFFUSION WINDOWS IN THE THIN OXIDE REGIONS. AFTER A DIFFUSION STEP WHICH INCLUDES DEPOSITION OF A PHOSPHORUS DOPANT IN THE DIFFUSION WINDOWS FROM THE VAPOROUS PHASE AND A DRIVE-IN STEP, A THERMAL OXIDATION STEP IS CARRIED OUT WHICH COVERS THE DIFFUSED WINDOW REGIONS AND THE POLYSILICON GATES AND THICK OXIDE REGIONS LEAVING THE EXPOSED NITRIDE PORTIONS UNAFFECTED. IN A SUBSEQUENT MASKING STEP, DIFFUSION CONTACT WINDOWS AND SILICON GATES CONTACT WINDOWS ARE OPENED. THEN, METALLIZATION IS DEPOSITED EVERYWHERE AND DELINEATED TO FORM METAL GATES AND CONTACTS TO BOTH DIFFUSIONS AND SILICON GATES. METAL IS DELINEATED AND FORMED IN EACH OF THE EXPOSED SILICON NITRIDE REGIONS ONE OF WHICH IS A SELF-ALIGNED CHANNEL REGION FOR A METAL GATE FIELD-EFFECT TRANSISTOR. OTHER METAL GATES FOR A CHARGE COUPLED DEVICE ARE POSITIONED BY VIRTUE OF THE PRESENCE OF ADJACENT POLYSILICON GATES AND ARE INSULATED FROM THE SUBSTRATE BY A THIN OXIDE AND NITRIDE LAYER AND FROM THE SILICON GATES BY A LAYER OF THERMALLY GROWN SILICON DIOXIDE ON THE SURFACE OF THE SILICON GATES. THE RESULTING STRUCTURE INCLUDES A METAL GATE FIELD-EFFECT TRANSISTOR, A SELF-ALIGNED SILICON GATE FIELD-EFFECT TRANSISTOR, AND A CHARGE COUPLED DEVICE ON THE SAME WAFER. BY USING AN ADDITIONAL MASKING STEP OVER THAT REQUIRED FOR THE FORMATION OF SILICON SELF-ALIGNED GATES ALONE, METAL GATES WHICH ARE EITHER SELF-ALIGNED BY VIRTUE OF ADJACENT POLYSILICON GATES OR BY VIRTUE OF THE PRESENCE OF A SELF-ALIGNED CHANNEL ARE THUS OBTAINED. IN ADDITION, A RANDOM ACCESS CHARGE COUPLED DEVICE WHICH INCORPORATES A METAL TRANSFER GATE AND A POLYSILICON STORAGE PLATE IS ALSO DISCLOSED. THE STRUCTURE RESULTS FROM THE ABOVE DESCRIBED FABRICATION PROCESS AND IS STRUCTURALLY UNIQUE IN THAT THE METAL GATE IS DISPOSED IMMEDIATELY ADJACENT TO A DIFFUSION REGION WHICH ITSELF IS DISPOSED UNDER A THICK OXIDE LAYER. IN ADDITION, THE POLYCRYSTALLINE SILICON STORAGE PLATE IS SPACED FROM THE METAL GATE BY A LAYER OF THERMALLY GROWN SILICON DIOXIDE.

Electroluminescent semiconductor device for generating ultra violet radiation

Abstract: An electroluminescent semiconductor device including a body of crystalline gallium nitride, a layer of silicon nitride on a surface of the body, a metal layer on the silicon nitride layer and an ohmic metal contact on the body. When a bias is applied between the metal layer and the contact which with respect to the ohmic contact is first negative and then positive, ultra violet radiation will be emitted from the body.

Electrical Charactristics of Polycrystalline Silicon-Silicon Nitride-Silicon Dioxide-Silicon Structures

Abstract: The influences of annealing at high temperatures and of impurity diffusion such as phosphorus and boron on fast surface states and instabilities under bias-temperature treatment were investigated. The fast surface states and instabilities increased by annealing in nitrogen, argon and oxygen. The instabilities were caused by the increase in conductivity of silicon nitride films. It was supposed that during annealing, localized strains under polycrystalline silicon electrodes were absorbed by silicon nitride films which in turn underwent large deformation and became filled with high density traps responsible for the increase of conductivity of silicon nitride films. Annealing in hydrogen reduced fast surface states and improved the instabilities. These phenomena are explained by the elimination of traps on SiO2–Si interface and in the bulk of silicon nitride.

Process of fabricating silicon photomask

Abstract: AN IMPROVED "SEE-THROUGH" PHOTOMASK OF SILICON PATTERNED ON GLASS IS PRODUCED BY THE LOW-TEMPERATURE DEPOSITION OF SILICON, FOLLOWED BY THE LOW-TEMPERATURE DEPOSITION OF SILICON NITRIDE OR SILICON OXIDE ON THE SILICON. THE NITRIDE OR OXIDE IS THEN PATTERNED BY SELECTIVE ETCHING FOR USE AS AN ETCH-RESISTANT MASK IN THE SELECTIVE ETCHING OF THE SILICON TO PRODUCE THE PHOTOMASK. PREFERABLY, THE NITRIDE OR OXIDE PATTERN IS LEFT ON THE SILICON PATTERN AS AN ANTI-REFLECTION COATING.

Improved bending strength silicon nitride components - obtd. by heat treatment after hot pressing

Abstract: The bending strength and impact resistance of silicon (oxi)nitridge ceramics, produced by hot pressing from powder contg. a small propn. of a sintering promoting agent at press. 100-400 kp/cm2 and temp. 1500-1900 degrees C, is improved, after cooling, by heat treatment pref. for 0.5-40 hrs. at 1100-1800 degrees C in a vacuum or O-free atmos., followed by controlled rate fast cooling. The treatment results in increases of the bending strength of >=1/3.