International Business Machines Corporation

Melvin Berkenblit

Arnold Reisman

Robert O Lussow

See Ark Chan

Frank Benjamin Kaufman

Takeshi Takamori

Kyu C Park

Charles J Merz, Iii

Stanley Zirinsky

Dennis C Green

Moshe Balog

See-Ark Chan

Joan B Landermann

A heat dissipating system for cooling circuit chips or modules is described. The disclosed system includes circuit chips or modules which are vertically mounted, a gas at an elevated pressure being contained within an encased module for providing an enhanced thermal coupling between the chips or modules contained therein, and the walls of the encased module, whereby heat removal from the chips or modules is increased. This enhanced thermal coupling is combined with a reduction in the temperature of the walls of the encased modules so as to reduce the thermal resistance between the surrounding gas and the chips or modules to be cooled, whereby heat removal from the circuit chips or modules is substantially increased.

Vertical wall elevated pressure heat dissipation system

An elevated pressure reactor apparatus for oxidizing or annealing specimens of the type including a reaction tube for containing the specimen surrounded by a heating furnace and enclosed in a pressure chamber, the apparatus incorporating a unique single gas flow feature, an improved multi-element furnace structure, a retrograde closure for the reaction tube to prevent gas flow back from the pressure chamber, a magnetically connected driving mechanism for a specimen support boat, and concentric gas entrance and exit tubes wherein exiting gas pre-heats the entering gas.

Single gas flow elevated pressure reactor

There are provided quaternary etchants comprising ethylenediamine, pyrocatechol, water and a diazine as catalyst for the etching of polycrystalline or single crystal silicon over a wide temperature and etch rate range. The etchants provide residue free dissolution, and have etch rates which are essentially unchanged when exposed to oxygen. The etch rate of the etchants can be modulated by the change in concentrations of water and/or pyrocatechol. There is also provided a method for etching polycrystalline or single crystal silicon using the etchants of this invention.

Method for etching silicon and a residue and oxidation resistant etchant

A method for controlling the etch rate of a quaternary etchant comprising ethylene diamine, water, pyrocatechol and a diazine. The etching rate is catalyzed and controlled by controlling the amount of the diazine present in the etchant. A method for the controlled etching of silicon is also disclosed.

Method of controlling silicon wafer etching rates-utilizing a diazine

The invention provides a method for forming a protective silicon carbide (SiC) film on a silicon (Si) substrate. The method permits the formation of silicon carbide on the Si substrate on all surfaces simultaneously. The process is highlighted in that the silicon substrate to be coated is placed in a susceptor having tantalum carbide surfaces and which has a high purity ambient. The substrate is heated at a temperature about 1250.degree. C to remove native SiO.sub.2 from its surface. The system is then cooled to a temperature of about 900.degree. C and methane is added for about 30 minutes to thereby deposit a layer of carbon which is further reacted with the Si substrate at 1250.degree. C to form a smooth, pin hole free SiC film. SiC layers are also formed by a one step reaction in which methane is reacted directly with Si at 1250.degree. C.

Method for forming smooth self limiting and pin hole free SiC films on Si

A method for etching at least one aperture having a defined crystallographic geometry in single crystals which includes masking the crystal to protect predetermined portions thereof from being etched, and then anisotropically etching with a mixture of sulfuric acid and phosphoric acid.

Process for etching holes

An in situ process is disclosed for fabricating gas discharge display panels in a sequential seal, bake-out and backfill mode of operation. The single thermal cycle process involves placing unassembled panel parts in a controlled gas ambient furnace system with required seal frame, evacuating said furnace and backfilling with an appropriate ambient atmosphere to an appropriate pressure while heating the furnace. During the heating, the furnace is repeatedly evacuated to moderate vacuum and refilled to some predetermined pressure. The furnace is heated to just above the glass transition temperature of the seal frame in this evacuate-refill mode, then held for some time to achieve outgassing of both panel parts and furnace chamber. Thereafter, the furnace chamber is refilled to one atmosphere and further heated to complete the sealing of the panel. The panel is then cooled to approximately 300.degree. C, still under one atmosphere, after which the evacuate-refill cycle is continuously repeated as the temperature is lowered down to the temperature of tip-off using the refill gas for the pressurization. The panel is refilled to an appropriate pressure at elevated temperature such that at room temperature the pressure is the desired pressure and the panel is tipped off. The process of successive evacuations and backfillings at the appropriate portions of the cycle are highly desirable for cleaning of the panel parts via contaminant dilution.

Gas discharge display panel fabrication

A process for controlling the softening point and for providing a preselected softening point of solder glass which comprises bubbling oxygen-containing gas through a homogeneous melt of a solder glass containing copper oxide at a temperature and oxygen partial pressure predetermined to provide the desired preselected softening point of the solder glass and for a time sufficient to achieve equilibrium of the reaction Cu.sub.2 O+1/2O.sub.2 .revreaction.2CuO.

Method of controlling the softening point of solder glass

A polishing method for single crystal dielectrics such as sapphire and magnesium spinel is disclosed. A single crystal wafer of sapphire or magnesium spinel is immersed in a mixture of sulphuric and phosphoric acid in a range of mixtures of 9 parts sulphuric acid to 1 part phosphoric acid to 1 part sulphuric acid to 9 parts phosphoric acid by volume while the mixture is held at a temperature in the range of 200.degree.-325.degree.C. The rate of polishing as well as the quality of polishing of the wafers of sapphire or magnesium spinel is orientation sensitive and polishing is achieved for magnesium spinel having the orientations (100) and (110). Polishing is achieved for sapphire having the orientations (0001), (1123), (1100), (1124), (1120) and (0112). A wafer to be polished is suspended in the heated solution and may be rotated slowly. Nonpreferential material removal rates of fractions of a micron per minute are obtained. Crystals of both sapphire and spinel having the above-mentioned orientations may be polished in a preferred temperature range of 250.degree.-300.degree.C. The preferred polishing mixture for sapphire is 1 part sulphuric acid to 1 part phosphoric acid by volume at a temperature of 285.degree.C. For magnesium spinel, the preferred mixture is 3 parts sulphuric acid to 1 part phosphoric acid at a temperature of 250.degree.C. The polishing technique of the present invention provides planar, polished surfaces which are free of insoluble residues on the polished surface.

Chemical polishing of single crystal dielectrics

A glass composition comprises a low glass transition temperature glass and a higher glass transition temperature glass, which glasses are uniquely capable of forming together a continuous vitreous phase over their entire compositional range. During thermal cycling, the low glass transition temperature glass flows out and solubilizes the higher glass transition temperature glass to thereby synthesize in situ a new glass. The low glass transition temperature glass is composed of 14.1% SiO.sub.2, 72.8% PbO, 12.5% B.sub.2 O.sub.3, 0.2% Al.sub.2 O.sub.3, 0.1% CaO, 0.2% Na.sub.2 O, and 0.1% MgO, and the higher glass transition temperature glass is composed of 71.11% SiO.sub.2, 2.38% Al.sub.2 O.sub.3, 7.13% CaO, 14.45% Na.sub.2 O, 3.76% MgO, 0.30% of K.sub.2 O, 0.13% B.sub.2 O.sub.3, and 0.74% PbO.

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Yorktown Heights, NY, United States of America

Melvin Berkenblit