Heraeus Quarzschmelze Gmbh

W.c. Heraeus Gmbh

Karl A Schulke

Heinz Herzog

Christopher J Bayne

Heinrich Mohn

Geoffrey Hayward

Alfons Gutermann

Tubular components made out of quartz glass or fused quartz, such as tubes, bells, hoods, or pans, with a flange fused or welded onto them are known. To improve cooling such a tubular component, especially the sealing surfaces of the flange, heat conduction and heat radiation in the vicinity of the flange are extensively avoided and, to make it possible to create long-diameter tubular components, the flange is designed hollow and narrow-walled, whereby a coolant, preferably water or a gas, can be conveyed through the hollow space in one preferred embodiment for purposes of interior cooling or the hollow space can be packed with a heat-insulating material.

Tubular component made out of quartz glass with a flange

An oven for the heat treatment of semiconductor substrates, especially a diffusion oven, having an upright, heatable quartz tube and a support system made of up rods or tubes into which one or more diffusion racks can be inserted which accommodate the wafer-like substrates separated from one another and substantially parallel to one another. To create a vertically operated oven having a rheologically efficient construction in which the support system for holding the diffusion racks will be highly variable, the support system has at least two vertical supports arranged parallel to one another, on which at least one rack rest 9 is disposed, on which rack rest the diffusion rack is placed such that the substrate wafers 8 stand substantially on edge during the treatment.

Oven for the heat treatment of semiconductor substrates

A rack for supporting wafers has a pair of parallel struts with kerfs therealong for supporting the wafers. A dummy wafer is attached to the struts near each end of the struts to connect the struts structurally as the rack and serve as rack-handling handles. The dummy wafers are parallel to the adjacent kerfs and thus the wafers therein and dimensioned similarly to the wafers for providing favorable gas and heat distribution when a wafer loaded rack is placed in a furnace. This adapts the rack for diffusion treatment of semiconductor wafers.

Rack for supporting wafers for treatment

An epitaxy bell of transparent fused silica is provided with a flanged, thick-walled tubular piece of transparent fused silica on the side on which a process gas is exhausted. The wall thickness of the constricted portion of the bell is increased toward the transparent fused silica tubular piece.

Transparent fused silica bell for purposes relating to semiconductor

A bell made of opaque fused silica and intended for use in the deposition of polycrystalline silicon is assembled from at least three individual sections. The sections are joined to one another at end flanges with gaskets between the flanges. The lengths of the individual sections are determined by the temperature distribution along the bell in use.

Bell of opaque fused silica

To connect together tubular elements, such as pipes and the like, made of materials which are difficult to machine and handle, and which are expensive, such as quartz glass, or quartz materials or quartz-ceramic goods used, for example, in laboratory or chemical processing apparatus, the end portions of the tubular elements are formed with a circumferential groove or recess in which a spring ring made of metal, fiber-reinforced plastic, or the like, is snapped, the spring ring (3) being clamped at its external, projecting surface by a conical surface (8) on a flange ring (4) and a similar conical surface (8) on a counter ring, the flange ring and the counter ring being clamped by connecting bolts (6); two such elements can be connected together by passing connecting bolts (10) through aligned openings (7) in the flange rings; preferably, the connecting bolts are spring-loaded (11). The engagement angles of the conical surfaces (8) on the rings are, for example, about 38.degree. each with respect to a plane passing transversely through the axis of the tubular quartz goods.

Flange connection for quartz tubes

A generally trough-like elongated element is formed of quartz glass, open at the top, in which the side walls (2) which, preferably, have inclined portions (4) merging with the bottom wall (1) of the trough, are formed with through-slits (3), and the bottom wall is formed with slots (5) cut therein, leaving, however, the end portions solid and uncut; the end portions are formed with positioning or alignment notches (6) extending in a direction transverse to the bottom wall which, preferably, is formed with a recess or notch for engagement with a transport apparatus. The side walls preferably have holes extending, in longitudinal alignment, through the solid end portions to permit passage of the tines of a handling fork (8) therethrough. The slits (3) and the slots (5) provide for three-point suspension of disk or plate-like semiconductor substrates for handling and introduction, for example, into a treatment or diffusion furnace or tube.

Semiconductor substrate handling tray

Bell of translucent fused silica having an inner layer of transparent fused silica for the precipitation of polysilicon. The thickness of the transparent fused silica layer increases continuously towards the open end of the bell while the total wall thickness of the bell is kept constant. The thickness increase of the transparent fused silica layer begins preferably beyond the center of the total length of the bell. The thickness of the transparent fused silica layer increases by at least half of the thickness which it has in the top part of the bell.

Bell of translucent fused silica for the precipitation of polysilicon

An improved method for the heat treatment of quartz-glass tubes at temperatures above 1200.degree. C. is disclosed wherein a pressure is maintained within the glass tube which is 3 to 110 mm Hg higher than the pressure on the external surface of the quartz tube over the heated area of the tube for at least the length of time that a temperature of 1200.degree. C. is exceeded. The process is particularly useful for the treatment of quartz-glass tubes within which silicon wafers are disposed for the purpose of diffusing doping agent into silicon wafers or of depositing doped epitaxial layers on silicon wafers.

Heat-treating method for semiconductor components

In a refractory protective tube for the heat treatment of semiconductor components which is constricted at one end and at such constricted end is provided with a treating or working gas inlet, said tube having opposite to said gas inlet a closed end provided with a gas outlet, the improvement for the prevention of back diffusion of ambient air wherein said closed end is closed by a cover which is fastened to a holding bracket which is movably suspended from the tube.

Refractory protective tube for the heat treatment of semiconductor

To provide a flange connection between two materials of substantially different thermal coefficient of expansion, for example a glass, typically quartz glass or ceramic material and a metallic material, for example cast iron or steel, with an interposed sealing ring of an elastomer, for example rubber, the flange seating surfaces are formed at an angle of inclination with respect to the central axis of the tubes to define a shallow cone having a cone angle (.alpha.) defined by arc tan .mu..sub.O, in which .mu..sub.O is the coefficient of friction between the material of the sealing ring and the adjacent material which includes the theoretical core of the cone, typically the glass or ceramic element forming the connection, the maximum cone angle being 45.degree.. One of the elements, typically the metal element, can be formed with a groove to receive a portion of the sealing ring and locate it in position.

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Neuberg, Germany

Karl A Schulke