Semiconductor processing apparatus and methods for calibrating a semiconductor processing apparatus

A semiconductor processing apparatus is disclosed that may include a reaction chamber joined by an upstream inlet flange and a downstream outlet flange wherein a longitudinal direction of the chamber extends from the inlet flange to the outlet flange and a plurality of ribs are provided on an outer surface of at least an upper chamber wall. The semiconductor processing apparatus may also include at least one array of heating elements disposed above the reaction chamber and at least one variable positioning device coupled to the at least one array of heating elements and configured to controllably adjust the position of the at least one array of heating elements relative to the position of the plurality of ribs.

FIELD OF INVENTION

The present disclosure generally relates to a semiconductor processing apparatus and methods for calibrating a semiconductor processing apparatus.

BACKGROUND OF THE DISCLOSURE

High-temperature reaction chambers may be used for depositing various material layers onto semiconductor substrates. A semiconductor substrate, such as, for example, a silicon substrate, may be placed on a substrate support inside a reaction chamber. Both the substrate and the support may be heated to a desired set point temperature. In an example substrate treatment process, reactant gases may be passed over a heated substrate, causing the chemical vapor deposition (CVD) of a thin layer of the reactant material onto the substrate. Throughout subsequent depositions, doping, lithography, etch and other processes, these layer are made into integrated circuits.

Various process parameters may be carefully controlled to ensure the high quality of the deposited layers. An example of one such process parameter is the substrate temperature uniformity. During CVD, for example, the deposition gases may react within particular prescribed temperature ranges for deposition onto the substrate. A change in temperature uniformity across a substrate may result in a change in the deposition rate and an undesirable layer thickness non-uniformity. Accordingly, it is important to accurately control the substrate temperature uniformity to bring the substrate to the desired temperature and temperature uniformity before the treatment begins and to maintain the desired temperature and uniformity throughout the process.

In certain applications, the pressure within a reaction chamber, such as a quartz reaction chamber configured for CVD, may be reduced to levels much lower that the surrounding ambient pressure. In such reduced pressure applications the quartz reaction chamber may comprise a cylindrical or spherical chamber since the curved surfaces of such quartz reaction chambers may be better suited to withstand the inwardly directed force resulting from the reduced pressure process. However, when positioning a flat substrate for chemical vapor deposition purposes, where the deposition gases flow parallel to the substrate, it may be desirable that the chamber walls be parallel to the flat surface of the substrate, to obtain uniform deposition on the substrate surface. Uniform deposition may be critical to obtain a high yield of acceptable products to be fabricated from such substrates. However, a quartz reaction chamber comprising flat chamber walls may collapse inwardly when processes comprise reduced pressures when compared with an outwardly convex chamber wall of similar size and thickness.

To handle the inwardly directed forces on a flat chamber wall, gussets or ribs may be provided on the exterior of the walls extending generally perpendicular to the wall to which they are joined, as may be seen in U.S. Pat. No. 4,920,918, issued on May 1, 1990, titled PRESSURE RESISTANT THERMAL REACTOR SYSTEM FOR SEMICONDUCTOR PROCESSING, all of which is hereby incorporated by reference and made a part of this specification. One disadvantage of such a quartz reaction chamber design is that even though quartz is substantially transparent to the radiant lamp energy, provided by radiant lamp heaters, the rib sections present a region of much thicker quartz and may refract the lamp energy to a great extent compared to the flat chamber walls thereby attenuating the lamp energy reaching certain sections of the substrate within the reaction chamber. This attenuation of energy causes cooler regions (i.e., shadows) on the substrate. Such non-uniformity of temperature on the substrate surface reduces the quality of the films that may be deposited, particularly for process conditions that are temperature-sensitive.

Nominally identical CVD tools utilized for wafer deposition may comprise some variance from tool to tool. For example, the reaction chambers utilized in CVD processes may each have a characteristic thermal environment which may, in turn, affect the wafer temperature during a deposition process. The reaction chamber may be fabricated from quartz materials and processes utilized in the fabrication and reworking of the quartz reaction chamber may result in variation in the features of the quartz reaction chamber, such as, for example, critical dimensions, materials quality, refractive properties, etc. In addition, the components within and surrounding the reaction chamber may vary in position and optimal function adding additional variance. The variation in the reaction chambers may be undesirable for high volume manufacturing where multiple reaction chambers may perform the same process recipe with the expectation that the process results are essentially the same. For example, for a CVD process, the resulting deposited layers are expected to possess uniform thickness, carrier mobility, refractive indices, stress, etc.

To overcome the problems, which may arise due to variation in CVD tools, systems and processes known as “tool-to-tool matching” may be employed. However, existing “tool-to-tool matching” systems and processes may be limited, time consuming, cost prohibitive and may not provide effective methods of thermally calibrating multiple chemical vapor deposition systems.

SUMMARY OF THE DISCLOSURE

In accordance with at least one embodiment of the disclosure, a semiconductor processing apparatus is disclosed. The semiconductor processing apparatus may comprise: a reaction chamber comprising; an upper chamber wall and a lower chamber wall connected by vertical sidewalls, the chamber walls being joined by an upstream inlet flange and a downstream outlet flange wherein a longitudinal direction of the chamber extends from the inlet flange to the outlet flange. The reaction chamber may further comprise a plurality of ribs provided on an outer surface of at least the upper chamber wall, the plurality of ribs being orientated transversely to the longitudinal direction of the chamber. The semiconductor processing apparatus may also comprise: at least one array of heating elements disposed above the reaction chamber and at least one variable positioning device coupled to the at least one array of heating elements and configured to controllably adjust the position of the at least one array of heating elements relative to the position of the plurality of ribs.

The current disclosure may also comprise a method of calibrating a semiconductor processing apparatus and the method may comprise: providing a reaction chamber comprising; an upper chamber wall and a lower chamber wall connected by vertical sidewalls, the chamber walls being joined by an upstream inlet flange and a downstream outlet flange wherein a longitudinal direction of the chamber extends from the inlet flange to the outlet flange. Providing a reaction chamber may further comprise; providing a plurality of ribs provided on an outer surface of at least the upper chamber wall, the plurality of ribs being orientated transversely to the longitudinal direction of the chamber. The method of calibrating a semiconductor processing apparatus may further comprise: providing at least one array of heating elements disposed above the reaction chamber and adjusting at least one variable positioning device coupled to the at least one array of heating elements to controllably adjust the position of the array of heating elements relative to the position of the plurality of ribs.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

As used herein, the term “substrate” may refer to any underlying material or materials that may be used, or upon which, a device, a circuit or a film may be formed.

The embodiments of the disclosure may include a semiconductor processing apparatus and a particular semiconductor processing apparatus configured for chemical vapor deposition processes. The semiconductor processing apparatus of the current disclosure may comprise a quartz reaction chamber which may operate at reduced pressure and may therefore comprise a plurality of ribs which strengthen the reaction chamber and prevent unwanted implosion when operating at reduced pressure. The semiconductor processing apparatus of the present disclosure may allow for increased control of the temperature uniformity and the thermal environment within the quartz reaction chamber by providing one or more variable positioning devices that are configured for controllably adjusting the position of an array of heating elements relative to the position of the plurality of ribs comprising the quartz reaction chamber. The ability to controllably position and reposition the array of heating elements relative to the plurality of ribs making up the quartz reaction chamber allows for the thermal calibration of a semiconductor processing apparatus and the thermal matching of multiple semiconductor processing apparatus, as well as allowing for an improved temperature uniformity difference across the upper surface of at least one substrate provided within the quartz reaction chamber.

In particular embodiments of the disclosure, the quartz reaction chamber provided for the chemical vapor deposition process may comprise a quartz reaction chamber which has undergone a refurbishment process. In greater detail, once a quartz reaction chamber has been utilized multiple times for chemical vapor deposition processes, it may require processing to restore the quartz reaction chamber back to its original state (or as close as possible to its original state). The processes utilized in restoring the quartz reaction chambers are commonly referred to as “refurbishment processes” and may include, but are not limited to, thermal processing and chemical processing. For example, a quartz reaction chamber refurbishment process may comprise a “fire polishing” process to eliminate micro cracks in the surface of the quartz reaction chamber and in addition the quartz reaction chamber may also be annealed in a high temperature oven (e.g., 1100° C.) to relieve stress in the quartz reaction chamber. Although the refurbishment of quartz reaction chambers enables the quartz reaction chambers to be utilized and reutilized for extended periods of time, the refurbishment process may also alter the critical dimensions of the quartz reaction chamber, which in turn may alter the relative position of an array of heating elements positioned above the quartz reaction chamber during a chemical vapor deposition process. The semiconductor processing apparatus and methods of the current disclosure enable the use of refurbished quartz reaction chambers without degradation in the thermal characteristics, i.e., the thermal uniformity, of the quartz reaction chamber and associated chamber elements.

FIG.1illustrates a non-limiting example embodiment of a reaction chamber100that may be utilized for reduced pressure chemical vapor deposition processes. The reaction chamber100may be utilized as part of the semiconductor processing apparatus200(ofFIG.2) of the current disclosure. With reference toFIG.1andFIG.2, the reaction chamber100may comprise an elongated, generally flattened configuration. The non-limiting example reaction chamber100ofFIG.1may comprise an upper wall102with an outer surface102A and an inner surface102B, and a lower wall104A with an outer surface and an inner surface104B. The upper chamber102and the lower chamber wall104are connected by vertical side walls106and108. The chamber walls102,104,106and108may be joined by an upstream inlet flange110and a downstream outlet flange112. Upstream and downstream relate to the direction of process gas flow through the reaction chamber100and are synonymous in the present disclosure with front and rear, as well as with frontward and rearward.

Alternatively, the reaction chamber100may have configurations other than the flattened configuration illustrated inFIG.1. For example, the reaction chamber100may have a tent-shaped cross sectional shape, wherein the upper wall102and/or the lower wall104have a peak. In another embodiment, the upper/lower walls102and104may be rounded, giving the reaction chamber100a generally ovoid cross-sectional shape. It will be appreciated that in other embodiments, the upper/lower walls102and104of the reaction chamber100can be formed having other shapes in addition to the shapes discussed above, as well as combinations thereof.

In some embodiments, the reaction chamber height is less than the reaction chamber width. In this respect a longitudinal direction for the reaction chamber100extends from the inlet flange110to the outlet flange112, or along the section line114-114. A lateral direction extends between the sidewalls106and108, or transversely to section line114-114. The height direction is perpendicular to both the longitudinal and lateral axes. In some embodiments of the disclosure the reaction chamber100has a length of about 760 mm, a width of about 490 mm, and a height of about 160 mm.

In some embodiments, both the upper wall102and the lower wall104comprise thin, flat plate-like elements having a rectangular shape. A plurality of ribs116extend from the outer surface102A of the upper wall102, and a plurality of ribs118extend from the outer surface104A of the lower wall104. All of the ribs116and118are oriented lengthwise transversely to the section line114-114ofFIG.1, orientated transversely to the longitudinal direction of reaction chamber100. As shown inFIG.2, each of the ribs116may be positioned directly above and aligned with a corresponding one of the ribs118. Thus the ribs116and118comprise pairs of upper and lower ribs. In some embodiments illustrated inFIG.1andFIG.2, twelve pairs of ribs are utilized with approximately eight pairs of ribs being provided above and below the susceptor202disposed within reaction chamber100(ofFIG.2). In other embodiments, however, greater or fewer pairs of ribs may be used depending on the desired structural integrity of the reaction chamber100. In some embodiments of the disclosure, corresponding pairs of the upper ribs116and the lower ribs118may not be aligned with one another. Thus, the upper ribs116and the lower ribs118may be advantageously be fused to the reaction chamber with different orientations, alignments and/or spacing between the adjacent ribs depending on the desired level of structural integrity of the reaction chamber100.

FIG.2illustrates a cross-sectional view of a semiconductor processing apparatus200, including the semiconductor reaction chamber100ofFIG.1, and illustrates at least one array of heating elements204disposed above the reaction chamber100. In some embodiments of the disclosure, the at least one array of heating elements204may comprise an upper heating array and may be housed in an upper heating housing206(as illustrated inFIG.2by dashed line100). The semiconductor processing apparatus200ofFIG.2may also comprise an additional array of heating elements208disposed beneath the reaction chamber100and housed in lower heating housing210. The additional array of heating elements208disposed beneath the reaction chamber100may be substantially the same as the array of heating element204disposed above the reaction chamber100.

In some embodiments, the at least one array of heating elements204disposed above the reaction chamber100may comprise a plurality of radiant heating lamps. As a non-limiting example embodiment of the semiconductor apparatus of the current disclosure,FIG.3Aschematically illustrates a plan view of the reaction chamber100comprising a plurality of ribs116, inlet flange110and outlet flange112.FIG.3Aalso illustrates the upper heating housing206, disposed above the reaction chamber100, and comprising the array of heating elements204. In some embodiments the plurality of radiant heating lamps204comprises a plurality of elongated tube type lamps, spaced-apart in a parallel relationship and also substantially parallel with the reactant gas flow path through the underlying reaction chamber100. In other words, in some embodiments of the disclosure the plurality of radiant heating lamps204are of a plurality of elongated tube type lamps disposed substantially parallel to the longitudinal direction of the reaction chamber, i.e., the plurality of radiant heating lamps204are orientated substantially perpendicular to the direction of the plurality of ribs116. In embodiments wherein the upper array of heating elements comprises a plurality of radiant heating lamps disposed substantially parallel to the longitudinal direction of the reaction chamber the lower array of heating elements disposed beneath the reaction chamber may also comprise a plurality of elongated tube type lamps which may be disposed substantially perpendicular to the longitudinal direction of the reaction chamber, i.e., the upper plurality of radiant heating lamps and the lower plurality of radiant heating elements are substantially perpendicular to one another.

As a further non-limiting example embodiment of the semiconductor apparatus of the current disclosure,FIG.3Bschematically illustrates a plan view of reaction chamber100comprising a plurality of ribs116, inlet flange110and outlet flange112.FIG.3Balso illustrates the upper heating housing206, disposed above the reaction chamber100, and comprising the array of heating elements204. In some embodiments, the plurality of radiant heating lamps204comprises a plurality of elongated tube type lamps, spaced-apart in a parallel relationship and also substantially perpendicular with the reactant gas flow path through the underlying reaction chamber100. In other words, in some embodiments of the disclosure the plurality of radiant heating lamps204are of an elongated tube type lamps disposed substantially perpendicular to the longitudinal direction of the reaction chamber, i.e., the plurality of radiant heating lamps204are orientated substantially parallel to the direction of the plurality of ribs116. In embodiments wherein the upper array of heating elements comprises a plurality of radiant heating lamps disposed substantially perpendicular to the longitudinal direction of the reaction chamber the lower array of heating elements disposed beneath the reaction chamber may also comprise a plurality of elongated tube type lamps which may be disposed substantially parallel to the longitudinal direction of the reaction chamber, i.e., the upper plurality of radiant heating lamps and the lower plurality of radiant heating elements are substantially perpendicular to one another.

As illustrated in bothFIG.3AandFIG.3B, the plurality of radiant heating lamps204are of an elongated tube type disposed substantially parallel and adjacent to one another. In some embodiments of the disclosure it may be desired to alter the relative position of an individual heating lamp within the array. For example, in some embodiments of the disclosure repositioning an individual radiant heating lamp204′ may provide a more uniform temperature profile within the reaction chamber100, therefore the apparatus of the current disclosure allows for the distance between the individual radiant heating lamps to be adjusted. As a non-limiting example embodiment,FIG.3Aillustrates radiant heating lamps204′ and204″ substantially parallel to one another and spaced apart from one another by a distance labelled as d. Therefore, in some embodiments of the disclosure the distance d between radiant heating lamps204′ and204″ may be increased or decreased depending on the desired thermal profile required within the reaction chamber100.

The plurality of radiant heating lamps204may be of a similar configuration. Each of the elongated tube type heating elements may comprise a high intensity tungsten filament lamp having a transparent quartz envelope containing a halogen gas, such as iodine. The lamps produce radiant heat energy in the form of full-spectrum light, transmitted through the reaction chamber walls, such as upper chamber wall102, without appreciable absorption. As is known in the art of semiconductor processing equipment, the power of the various radiant heating lamps may be controlled independently or in grouped zones in response to temperature sensors arranged in proximity to a substrate212disposed within the reaction chamber100, as illustrated inFIG.2.

The plurality of lamps204and208as illustrated inFIG.2andFIGS.3A and3Bare illustrated without showing a detailed supporting structure. One of skill in the art, however, will readily recognize a number of manners of mounting the lamps relative to the chamber walls, such as upper chamber wall102. In some embodiments of the disclosure, the at least one array of heating elements204disposed above the reaction chamber100may be disposed within an upper heating housing206. The upper heating housing206shown inFIG.2is of a simplified form and further illustration and discussion of the upper heating housing206will be given herein. However, it should be noted that in some embodiments, the upper heating housing206may be attached to a reaction chamber housing, which may support the reaction chamber100.

In some embodiments, each individual radiant heating lamp includes an integrally formed axially extending lug on each of its opposite ends and a suitable connection pin arrangement extending from each of the lugs for receiving connectors provided at the end of electrical conductors.

Referring back toFIG.2, the at least one array of heating elements204disposed above the reaction chamber100may be coupled to at least one variable positioning device, configured to controllably adjust the position of the at least one array of heating elements relative to the position of the plurality of ribs. In some embodiments of the disclosure, the at least one array of heating elements is coupled to at least two variable positioning devices, for example, as illustrated inFIG.2by the variable positioning devices214and216. In some embodiments, the at least one array of heating elements is coupled to a least three variable positioning devices, for example, as illustrated inFIG.3AandFIG.3Bby the variable positioning devices214,216and302.

As shown by non-limiting example semiconductor processing apparatus200ofFIG.2, at least one variable positioning device214is configured to controllably adjust the position of the at least one array of heating elements204in a direction substantially parallel to the longitudinal direction of the reaction chamber100. In other words, the variable positioning device positions and re-positions the array of radiant heating lamps in an x-axis, as illustrated inFIG.2. It should be appreciated that the variable positioning device214coupled to the at least one array of heating elements204may be coupled via the upper heating housing206and may include further coupling materials disposed between the variable positioning device214and the individual radiant heating lamps204.

In a further example embodiment, at least one variable positioning device216is configured to controllably adjust the position of the height of the at least one array of heating elements204relative to the position of the upper chamber wall102of reaction chamber100and particular related to the susceptor202disposed within reaction chamber100. In other words, the variable positioning device positions and re-positions the array of radiant heating lamps in a z-axis, as illustrated inFIG.2. It should be appreciated that the variable positioning device216coupled to the at least one array of heating elements204may be coupled via the upper heating housing206and may include further coupling materials disposed between the variable positioning device216and the individual radiant heating lamps204.

In yet a further example embodiment, at least one variable positioning device302(ofFIG.3A or3B) is configured to controllably adjust the position of the at least one array of heating elements204in a direction substantially perpendicular to the longitudinal direction of the reaction chamber100. In other words, the variable positioning device302positions and re-positions the array of radiant heating lamps204in a y-axis, as illustrated inFIG.3A. Again, it should be appreciated that the variable positioning device302coupled to the at least one array of heating elements204may be coupled via the upper heating housing206and may include further coupling materials disposed between the variable positioning device302and the individual radiant heating lamps204.

A number of variable positioning devices may be utilized for controllably adjusting the position and height of the at least one array of heating elements, for example, the variable positioning device may comprises at least one of a micrometer (either manual or actuated by a motor), a differential micrometer, or a piezo-electric actuator.

The variable positioning devices of the current disclosure may be configured to provide a desired placement of the at least one array of heating elements in a number of directions. For example, the at least one variable positioning device of the current disclosure may allow for the displacement of the at least one array of heating elements in one or more directions, including, but not limited, parallel to the longitudinal direction of the reaction chamber, perpendicular to the longitudinal direction of the reaction chamber, and may also controllably adjust the height of the at least one array of heating elements relative to the position of the upper chamber wall of the reaction chamber.

In some embodiments of the disclosure, the at least one variable positioning device may be configured to provide a displacement of the least one array of heating elements no greater than approximately 2 centimeter, or no greater than approximately 1 centimeter, or even no greater than approximately 0.5 centimeters. In addition, the at least one variable positioning device may be configured to provide an displacement accuracy of less than 0.1 millimeters, or less than 0.01 millimeters, or even less than 0.001 millimeters.

The semiconductor processing apparatus of the current disclosure may include additional elements. As illustrated inFIG.2, the semiconductor processing apparatus of the current disclosure may further comprising a substrate support comprising a susceptor202disposed within the reaction chamber100beneath the at least one array of heating elements204, the susceptor202being configured to support at least one substrate212, wherein the substrate support comprising the susceptor202has a central axis around which the substrate212may rotate. The at least one substrate212may be supported by a substrate support which may comprise a susceptor202which comprises a material opaque to radiant heat energy, such as graphite or silicon carbide, as is known in the art of semiconductor processing equipment. The susceptor202and the substrate212are held at a desired height within the reaction chamber100by a support structure, as shown inFIG.2. The susceptor202may be supported on arms220of a suitable support222connected to the upper end of a rotatable shaft224that extends through a tube226depending from the bottom wall of the reaction chamber104. The susceptor202is shown approximately level with the upper surface of a support plate226. This facilitates positioning the substrate212atop the susceptor202of the reaction chamber100. Further details regarding interior chamber support assemblies and other details about a semiconductor processing chamber can be found in U.S. Pat. No. 6,093,252, issued on Jul. 25, 2000, the entirety of which is hereby incorporated by reference and made a part of this specification.

The semiconductor processing apparatus of the current disclosure allows for greater control of the thermal environment within reaction chamber100. In some embodiments, the at least one array of heating elements is configured to provide a temperature uniformity difference across a surface of the at least one substrate of less than 1.5° C., or configured to provide a temperature uniformity difference across a surface of the at least one substrate of less than 0.5° C., or even configured to provide a temperature uniformity difference across a surface of the at least one substrate of less than 0.25° C. In some embodiments, the at least one substrate may comprise an exposed upper surface upon which a chemical vapor deposition process primarily proceeds. In some embodiments, the at least one substrate may comprise a substrate with a diameter greater than 25 millimeters, or greater than 100 millimeters, or greater than 200 millimeters, or greater than 300 millimeters, or even greater than 450 millimeters.

In some embodiments of the disclosure, the thermal uniformity within the reaction chamber and particularly, the thermal uniformity across the susceptor upon which the substrate(s) is disposed, may be further improved by utilizing one or more reflectors in combination with the array of heating elements disposed above the reaction chamber. In certain embodiments, the one or more reflectors may comprise a single piece reflector, i.e., the reflector may be fabricated from a single piece of material. In some embodiments of the disclosure the single piece reflector may comprise, a plurality of parabolic segments, each of the individual parabolic segments of the plurality being disposed above and adjacent to a radiant heating element. In alternative embodiments, a plurality of non-parabolic segments may be disposed above and adjacent to a radiant heating element.

In greater detail,FIG.4illustrates a cross section view through reference line228-228of the semiconductor processing apparatus200ofFIG.2and provides a detailed view through the reaction chamber100and the related components of the semiconductor processing apparatus of the current disclosure.FIG.4illustrates the susceptor202disposed within the reaction chamber100and tube226depending from the bottom wall104of the reaction chamber100through which mechanisms for rotation of susceptor202may be provided (not shown). Above the reaction chamber100is disposed the upper heating housing206, illustrated in the closed position, the upper heating housing206comprising upper heating housing wall402in contact with the reaction chamber housing404. Disposed within the upper heating housing206and coupled to the upper heating housing206via bracket406is the single piece reflector408. The single piece reflector408comprises a plurality of parabolic segments410, each of the individual parabolic segments410being disposed above and adjacent to an individual radiant heating lamp206. In some embodiments of the disclosure, each of the radiant heating lamps206is located at the focal point of the corresponding parabolic segment associated with that radiant heating lamp such that the radiated heat energy which impinges on the parabolic segment will be reflected down onto the underlying susceptor and the associated substrate(s).

In some embodiments of the disclosure, the one or more variable positioning devices may be configured to provide an adjustable distance between the radiant heating lamps and the single piece reflector and particularly the focal points of the plurality of parabolic segments. Such adjustment in the relative position of the radiant heating elements and the focal points of the plurality of parabolic segments enables that the radiant heating elements are positioned at the focal point of the corresponding parabolic element and such relative positioning may be achieved across multiple deposition systems such that multiple deposition systems are capable of providing substantially the same thermal environment within the reaction chamber. In alternative embodiments, the one or more variable positioning devices, which may adjust the relative height of the array of heating elements disposed above the reaction chamber, may be coupled to both the array of heating elements and the single piece reflector such that any adjustment in the relative height of the array of heating elements maintains the position of the single piece reflector relative to the array of heating elements.

The single piece reflector may also comprise a plurality of openings412which extend from the lower surface of the single piece reflector up to the upper surface of the single piece reflector. In some embodiments each individual opening, extending through the single piece reflector, may be disposed within an individual parabolic element and each opening may extend substantially parallel to the focal point of the parabolic element to proximate a peripheral edge of the single piece reflector. The plurality of opening may be utilized to allow air flow from above the reaction chamber100to the interior of upper heating housing206and such air flow may allow for cooling of the radiant heating elements and the reaction chamber.

In some embodiments of the disclosure the single piece reflector408may be manufactured from a single piece of material, such as, for example, a single piece of gold, aluminum, nickel, copper, metallized mylar, or multilayer dielectric materials.

The upper heating housing206is shown in more detail inFIG.5, which illustrates the upper heating housing206in the closed (down) position. The upper heating housing206may comprise one or more variable positioning devices214and302which may controllably position and re-position the array of heating elements disposed within upper heating housing206. In the non-limiting example embodiment illustrated inFIG.5, the variable positioning devices214and302may be utilized to adjust the position of the array of heating element in both the x-axis and the y-axis, i.e., parallel and perpendicular to the longitudinal direction of the underlying reaction chamber. The upper heating housing206may also comprise upper heating housing wall402and coupled to the upper heating housing wall402is a pyrometer stand502upon which one or more optical pyrometers may be disposed. In the non-limiting example embodiment illustrated inFIG.5, the pyrometer stand502is coupled to two pyrometers504A and504B which may be configured for sensing the temperature at pre-determined locations internal to the reaction chamber and external to the reaction chamber. For example, pyrometer504A may be configured for sensing the temperature within the reaction chamber and particularly for sensing the temperature of a substrate disposed upon the susceptor within the reaction chamber, whereas pyrometer504B may be configured for sensing the external temperature of the quartz reaction chamber.

Also disposed on the pyrometer stand502are positioning devices506A and506B, which may be utilized to enable precise positioning of the associated pyrometers504A and504B. As a non-limiting example embodiment, the positioning devices506A and506B coupled to the pyrometers504A and504B may comprise micrometers that may be configured for positioning and re-positioning the pyrometers504A and504B in both the x-axis and the y-axis. Upper heating housing206may also comprise one or more pyrometer cooling blocks508which are in thermal contact with the pyrometers504A and504B and provide a heat sink function to enable cooling of the pyrometers504A and504B. The upper heating housing206may also include one or more lift lid brackets510, which may be utilized for raising and lowering the upper heating housing.

FIG.6illustrates the upper heating housing206with the upper heating housing wall removed and various other ancillary components removed from within the upper heating housing206to enable a view of the functionality of the upper heating housing206. For example, the interior of upper heating housing206may include the single piece reflector408disposed above the array of radiant heating elements (not shown), the single piece reflector408including air flow openings412, extending from the upper surface of the single piece reflector and down to the lower surface of the single piece reflector, the plurality of air flow openings412utilized for providing cooling to the plurality radiant heating elements and the underlying quartz reaction chamber. The single piece reflector408may also include additional openings602which again may also extend from the upper surface of the single piece reflector through to the lower surface of the single piece reflector. The additional opening through the single piece reflector may be utilized for directing a light probe through the single piece reflector from the previously discussed pyrometers disposed upon the upper heating housing wall (as shown previously inFIG.5).

The interior of the upper heating housing206, as illustrated inFIG.6, may further comprise an xy-stage604which may be coupled to both the single piece reflector408(and the associated array of radiant heating elements) and one or more variable positioning devices which, as a non-limiting example, may include a micrometer214for adjustment of the positioning of the array of radiant heating elements in the x-axis and may further include micrometer302for adjustment of the position of the array of radiant heating elements in the y-axis.

In addition to variable positioning devices214and302, the interior of the upper heating housing206may comprise additional variable positioning devices216A and216B. In some embodiments of the disclosure, variable positioning devices216A and216B may comprise adjustment screws which are coupled to the xy-stage604and the single piece reflector408(and associated array of radiant heating elements). In non-limiting example embodiments, the adjustment screws may be turned clockwise to increase the distance between the array of radiant heating elements and the upper chamber wall and the susceptor disposed below and conversely the adjustment screws may be turned anti-clockwise to decrease the distance between the array of radiant heating element and the upper chamber wall and the susceptor disposed below. In some embodiments of the disclosure, three separate adjustment screws may be coupled to the xy-stage604to position and re-position the array of heating elements in the z-axis, i.e., adjusting the relative height of the array of radiant heating element to the upper chamber wall and particularly to the susceptor disclosed within the reaction chamber. In some embodiments, the adjustment screws may include a ball tip at a lower projection, which may be disposed in v-shaped groove disposed on a upper surface of the xy-stage604and that points radially inward to ensure that the single piece reflector center remains at the same position when the assembly expands and contracts during heating and cooling processes.

The upper heating housing206may further comprise one or more hinged mechanisms for connecting the upper heating housing to a reaction chamber housing. For example,FIG.6illustrates hinged mechanisms606A and606B, wherein a first surface of the hinged mechanism606A and606B is attached to the upper heating housing206and a second surface of the hinged mechanism606A and606B may be attached to a reaction chamber housing. Therefore, in some embodiments of the disclosure, the at least one array of heating elements are disposed in an upper heating housing and the upper heating housing is connected to a reaction chamber housing via one or more hinged mechanisms.

In some embodiments of the disclosure, the one or more hinged mechanisms are connected to the reaction chamber housing in a fixed position, i.e., the coupling between the upper heating housing and the reaction chamber housing is in a fixed, non-variable position, such that any variation in the position of the array of radiant heating elements in the upper heating housing relative to the plurality of ribs comprising the reaction chamber is achieved through adjustment of at least one of the variable positioning devices coupled to the array of heating elements. In other words, the variation in the position of the array of heating elements should not come from the action of raising and lowering of the upper heating housing relative to the reaction chamber. Therefore, in some embodiments, the one or more hinged mechanisms may be configured for raising and lowering the upper heating housing206relative to the reaction chamber100. For example, in some embodiments the one or more hinged mechanism is further configured for repositioning the upper heating housing206in a lowered position (i.e., a closed position) with a position tolerance relative to the plurality of ribs of less than 0.25 millimeters. For example,FIG.7illustrates the semiconductor processing apparatus200of the current disclosure with the upper heating housing206in the open position. The upper heating housing includes the upper array of heating elements204in the open, i.e., raised position, above the reaction chamber100which is disposed in reaction chamber housing702. As illustrates inFIG.7, the semiconductor processing apparatus200further comprises hinged mechanisms606which are utilized to attach the upper heating housing206to the reaction chamber housing702.

The embodiments of the disclosure may also provide methods for calibrating a semiconductor processing apparatus. For example, in some embodiments, the upper array of radiant heating elements may be disposed parallel to the plurality of ribs comprising the quartz reaction chamber and the plurality of ribs may cause a “shadowing” on the substrate disposed within the reaction chamber which may result in areas on the underlying substrate which are at a lower temperature than the average substrate temperature. In addition, the plurality of ribs may cause “light piping” of the radiant energy of the plurality of heating lamps which may result in areas on the underlying substrate which are at a higher temperature than the average substrate temperature. Therefore, the temperature across the substrate disposed on the susceptor may have a characteristic temperature profile which may be dependent on the relative position of the upper array of heating elements and the plurality of ribs. In some embodiments of the disclosure, the characteristic temperature profile may be tuned for a specific process, for example, as a non-limiting example, the temperature profile may be tuned such that a temperature gradient from the substrate edge to the substrate center exists.

During the operation and maintenance of a prior art semiconductor processing apparatus, such as a chemical vapor deposition system utilizing a quartz reaction chamber comprising a plurality of ribs and an upper array of heating elements, it may be necessary to raise the upper heating housing from the closed position, up to the open position and back again. During the operation to raise and lower the upper heating housing, the relative position of the array of heating elements relative to the plurality of ribs comprising the quartz reaction chamber may change and the characteristic temperature profile of the apparatus may be modified. The embodiments of disclosure may therefore provide methods for maintaining the relative position between the plurality of ribs and the upper array of heating elements thereby preserving the characteristic temperature profile of the semiconductor processing apparatus during extended operation and maintenance.

In addition, to enable “tool-to-tool matching” across multiple semiconductor processing apparatuses comprising multiple quartz reaction chambers, the characteristic temperature profile may need to be replicated across multiple semiconductor processing apparatus to ensure that multiple apparatus using the same process recipe produce substantially the same deposition results. Therefore, methods are needed to match the thermal environment of multiple semiconductor processing apparatus.

In some embodiments, a method of calibrating a semiconductor processing apparatus may comprise providing a reaction chamber, the reaction chamber comprising an upper chamber wall and a lower chamber wall connected by vertical side walls, the chamber walls being joined by an upstream inlet flange and a downstream outlet flange wherein the longitudinal direction of the reaction chamber extends from the inlet flange to the outlet flange. The reaction chamber of the methods of the disclosure may also comprise, a plurality of ribs provided on an outer surface of at least the upper chamber wall, the plurality of ribs being orientated transversely to the longitudinal direction of the reaction chamber. The method of calibrating a semiconductor processing apparatus may also comprise, providing at least one array of heating elements disposed above the reaction chamber. In some embodiment the method of calibrating a semiconductor processing apparatus may also comprise, adjusting at least one variable positioning device coupled to the at least one array of heating elements to controllably adjust the position of the array of heating elements relative to the position of the plurality of ribs.

In some embodiments the reaction chamber utilized in the semiconductor process apparatus of the present disclosure may comprise a refurbished reaction chamber, i.e., the reaction chamber may comprise a quartz reaction chamber which has undergone a refurbishment process as described herein. During the process of refurbishing the quartz reaction chamber the critical dimensions of the quartz reaction chamber may be modified, therefore when the refurbished quartz reaction chamber is reutilized within the semiconductor processing apparatus of the current disclosure it may be necessary to adjust the position of the upper array of heating elements relative to the plurality of ribs of the reaction chamber to provide the desired characteristic temperature profile.

In some embodiments the methods may comprise selecting the at least one array of heating elements to comprise a plurality of radiant heating lamps. In some embodiments the plurality of radiant heating lamps are of an elongated tube type disposed substantially parallel to the longitudinal direction of the reaction chamber. In alternative embodiments the plurality of radiant heating lamps are of an elongated tube type disposed substantially perpendicular to the longitudinal direction of the reaction chamber.

The embodiments of the disclosure may comprise methods for maintaining the relative position between an upper array of heating and a plurality of ribs comprising a quartz reaction chamber. Therefore, in some embodiments the methods may comprise selecting at least one variable positioning device to controllably adjust the position of the at least one array of heating elements in a direction substantially parallel to the longitudinal direction of the reaction chamber. In addition, in some embodiments the methods may comprise selecting at least one variable positioning device to controllably adjust the position of the at least one array of heating elements in a direction substantially perpendicular to the longitudinal direction of the reaction chamber. In further embodiments, the methods may comprise selecting the at least one variable positioning device to controllably adjust the height of the at least one array of heating elements relative to the position of the upper chamber wall of the reaction chamber.

In some embodiments of the methods of the disclosure the at least one array of heating elements is coupled to at least two variable positioning devices. For example, the upper array of heating elements may be coupled to a first variable positioning device and a second variable positioning device, wherein the first variable positioning device controllably adjusts the position of the array of heating elements in a direction substantially parallel to the longitudinal direction of the reaction chamber and the second variable positioning device controllably adjust the position of the array of heating elements in a direction substantially perpendicular to the longitudinal direction of the reaction chamber.

In some embodiments of the methods of the disclosure the at least one array of heating elements is coupled to at least three variable positioning devices. For example, the upper array of heating elements may be coupled to a first variable positioning device, a second variable positioning device, and a third variable positioning device, wherein the first and second variable positioning devices may adjust the position of the array of heating elements in the x-y axis and the third variable positioning device may controllably adjust the height of the least at least one array of heating elements relative to the position of the upper chamber wall of the reaction chamber.

In some embodiments the methods may further comprise selecting the at least one variable positioning device to provide a displacement of the at least one array of heating element no greater than approximately 2 centimeters, or no greater than approximately 1 centimeter, or no greater than approximately 0.5 centimeters.

It should be noted that two or more variable positioning devices may be utilized for adjusting the position of the array of heating elements in one particular direction. For example, two or more variable positioning devices may be utilized to controllably adjust the height of the at least one array of heating elements relative to the position of the upper chamber wall of the reaction chamber.

The method of calibrating a semiconductor processing apparatus may further comprise, providing a substrate support disposed within the reaction chamber beneath the at least one array of heating elements, the substrate support configured to support at least one substrate wherein the substrate support has a central axis around which the substrate support rotates. In additional embodiments the methods may comprise providing a single piece reflector comprising a plurality of parabolic segments disposed adjacent to the at least one array of heating elements.

The method of calibrating a semiconductor processing apparatus may further comprise selecting the at least one array of heating elements to be disposed in an upper heating housing and connecting the upper heating housing to a reaction chamber via one or more hinged mechanisms. The method may also comprise selecting the one or more hinged mechanisms to be connected to the reaction chamber housing in a fixed position. The fixed positioning of the one or more hinged mechanism(s) allows the repositioning of upper heating housing by raising and lowering the upper heating housing relative to the reaction chamber, wherein repositioning the upper heating housing comprises repositioning the upper heating housing to a lowered position to a position tolerance relative to the plurality of ribs of less than 0.25 millimeters.

In some embodiments of the disclosure, the reaction chamber may comprise a refurbished quartz reaction chamber and during the refurbishment processes the plurality of ribs comprising the reaction chamber may deviate from a nominal position determined prior to any refurbishment process, i.e., the nominal position of the plurality of ribs is determined for a new, unused reaction chamber. The nominal position of each of the plurality of ribs may be determined by measuring the distance from the inlet flange110(seeFIG.2) (or alternatively the outlet flange112) to each of the plurality of ribs116. Once the nominal position of each of the plurality of ribs has been determined, the reaction chamber can be utilized until it is determined that the reaction chamber requires a refurbishment process.

Once the refurbishment process on the reaction chamber has been completed, the method of the disclosure may continue by measuring the distance from the inlet flange to each of the plurality of ribs and calculating the deviation distance of each of the plurality of ribs from the previously recorded nominal position. The methods may continue by calculating the average deviation distance for the plurality ribs. The average deviation distance for the plurality of ribs may be recorded on the reaction chamber itself, for example, utilizing an etching process to produce a mark on the reaction chamber, i.e., on the inlet flange. The methods of the disclosure may continue by adjusting the position of the at least one variable positioning device coupled to the at least one array of heating elements by an amount substantially equal to the average deviation distance. Therefore the methods of the disclosure allow for the average deviation distance for the plurality of ribs to be determined and the position of the array of heating elements to be adjusted to compensate for any such average deviation distance of the plurality of ribs.

The methods of calibrating a semiconductor processing apparatus as described herein may reduce the temperature non-uniformity across a substrate disposed within the reaction chamber. For example, in some embodiments the at least one array of heating elements is configured to provide a temperature uniformity difference across the surface of at least one substrate of less than 1.5° C., or a temperature uniformity difference across a surface of the at least one substrate of less than 0.4° C., or even a temperature uniformity difference across a surface of the at least one substrate of less than 0.25° C. In some embodiments the at least one substrate may comprise a substrate with a diameter greater than 25 millimeters, or greater than 100 millimeters, or greater than 200 millimeters, or greater than 300 millimeters, or even greater than 450 millimeters.

The example embodiments of the disclosure described above do not limit the scope of the invention, since these embodiments are merely examples of the embodiments of the invention, which is defined by the appended claims and their legal equivalents. Any equivalent embodiments are intended to be within the scope of this invention. Indeed, various modifications of the disclosure, in addition to those shown and described herein, such as alternative useful combination of the elements described, may become apparent to those skilled in the art from the description. Such modifications and embodiments are also intended to fall within the scope of the appended claims.