Wafer processing device

Abstract

In order to provide a wafer processing device with improved processing accuracy and yield, the wafer processing device is provided with: a processing chamber 5 disposed inside a vacuum container 1; a sample table 4 disposed at the center of the lower part of the processing chamber and on which a wafer W to be processed is placed and supported; a gas introduction unit 6 that is disposed above the center of the upper surface of the sample table and has a gas introduction port 11 for introducing a gas for processing the wafer into the processing chamber; and a lamp unit 2 that is disposed around the gas introduction unit and constitutes the top surface of the processing chamber. The lamp unit is provided with: a plurality of ring-shaped lamps 2a that are arranged in multiple layers around the gas introduction unit and irradiate the wafer on the sample table with electromagnetic waves; and a reflection member 2 that is placed in a ring shape around the gas introduction unit above the plurality of lamps and has a reflection surface capable of reflecting the electromagnetic waves radiated from the plurality of lamps downward and toward a center-side region of the processing chamber, the height of the reflection surface increasing toward the gas introduction unit and decreasing toward the outer peripheral side from the gas introduction unit.

Description

Wafer Processing Equipment

[0001] The present invention relates to a wafer processing apparatus.

[0002] In semiconductor devices, the demand for lower power consumption and increased memory capacity is driving further miniaturization and three-dimensional device structures. In the manufacture of three-dimensional devices, because the structures are three-dimensional and complex, "isotropic etching," which allows etching in the lateral direction as well as the conventional "vertical etching" that etches in the vertical direction relative to the wafer surface, is required.

[0003] As an example of a conventional technique for performing isotropic etching with high precision using dry processing, an adsorption / desorption etching method is known, as described in Japanese Patent Laid-Open No. 2015-185594 (Patent Document 1). In this conventional technique, radicals generated by plasma are first adsorbed onto the surface of the layer to be etched of an object placed on a stage arranged inside a processing chamber, forming a reaction layer through a chemical reaction (adsorption process). Next, thermal energy is applied to desorb and remove this reaction layer (desorption process). Etching is performed by alternately and cyclically repeating this adsorption process and desorption process.

[0004] In this conventional technology, a lamp that emits ultraviolet or infrared electromagnetic waves is provided above a stage inside the processing chamber to apply thermal energy to the surface of the workpiece during the desorption process. During the desorption process, the workpiece is heated to a temperature at which the reactive layer on the surface of the layer to be etched sublimes in a short period of time.

[0005] Furthermore, Japanese Patent Laid-Open Publication No. 2020-097060 (Patent Document 2) discloses a stage inside a processing chamber arranged inside a vacuum vessel, with ring-shaped IR lamps emitting electromagnetic waves in the infrared range (hereinafter referred to as infrared light, IR, or IR light) arranged in multiple layers around a flow path directly above the stage through which reactive particles such as radicals are supplied into the processing chamber, and a reflector arranged above the IR lamps to reflect the IR light emitted from the IR lamps toward the upper surface of a wafer stage inside the processing chamber below or a wafer placed on that surface. With this configuration, this prior art irradiates the wafer with IR light reflected by the reflector along with IR light directly emitted from the IR lamps, thereby heating the wafer in a short period of time.

[0006] JP 2015-185594 A JP 2020-097060 A

[0007] As in the above-described conventional technology, particles (etchant) comprising reactive gases or vapors are supplied into the processing chamber of the vessel through an inlet located above the center of the upper surface of a sample stage, on which a wafer is placed and supported, and directed downward. The etchant contacts and adheres to the upper surface of the wafer, reacting with the surface of the target film, which is a film structure having multiple film layers including the target film layer previously disposed on the wafer's upper surface. The amount and size distribution of the reaction on the wafer's upper surface are significantly affected, for example, by the balance between the amount of etchant supplied and the reaction temperature.

[0008] The amount of etchant supplied varies greatly depending on the flow path of the reactive gas or vapor. Therefore, in order to suppress variations in the amount of etchant in the radial or circumferential direction (in-plane direction) of the wafer upper surface, a configuration is desired in which etchant particles that reach the wafer move from the center of the wafer toward the outer periphery and then are exhausted from the space between the sample stage and the inner wall of the processing chamber surrounding it. Specifically, a configuration is desired in which the gas inlet opening, the center of the wafer, and the central axis of the ring-shaped space located on the outer periphery of the sample stage and surrounding the outer peripheral sidewall of the sample stage are aligned or approximately aligned (coaxial exhaust). The above-mentioned prior art is equipped with this coaxial exhaust configuration.

[0009] On the other hand, in these conventional techniques, when a wafer is heated using IR (infrared) lamps, ensuring the heating rate and temperature distribution requires irradiating the entire wafer with IR light of a desired intensity and amount. However, in the above-described conventional techniques, when a gas inlet is located above the center of the wafer, the IR lamps are not located directly above the center of the wafer, but must be located around the gas inlet. This can impair the accuracy of adjusting the temperature of the wafer's central portion or its temperature distribution in the in-plane direction of the wafer to the desired value. This can lead to variations in the shape and relative reduction in accuracy of the central region of the wafer's top surface after etching, compared to the peripheral portion.

[0010] An object of the present invention is to provide a wafer processing apparatus with improved processing accuracy and yield.

[0011] The above-mentioned object is achieved by a wafer processing apparatus comprising: a processing chamber arranged inside a vacuum vessel; a sample stage arranged in the center of the lower part of the processing chamber and on which a wafer to be processed is placed and supported; a gas inlet section arranged above the center of the upper surface of the sample stage and having a gas inlet port for introducing gas for processing the wafer into the processing chamber; and a lamp unit arranged around the gas inlet section and constituting the ceiling of the processing chamber, wherein the lamp unit comprises a plurality of ring-shaped lamps arranged in multiple layers around the gas inlet section and irradiating electromagnetic waves onto the wafer on the sample stage; and a reflecting member arranged in a ring shape around the gas inlet section above the plurality of lamps and configured to reflect the electromagnetic waves radiated from the plurality of lamps downward and toward a region toward the center of the processing chamber, the height of the reflecting surface being higher near the gas inlet section and decreasing as it moves from the gas inlet section toward the outer periphery.

[0012] According to the present invention, electromagnetic waves emitted from the lamps are reflected upward in a predetermined direction, thereby enabling the wafer temperature and its distribution to be changed as desired. This allows the wafer temperature to be accurately kept within a range suitable for processing, thereby improving processing yield.

[0013] 1 is a longitudinal cross-sectional view schematically showing the configuration of a wafer processing apparatus according to an embodiment of the present invention; FIG. 2 is a longitudinal cross-sectional view schematically showing the configuration of a wafer processing apparatus according to a modified example of the embodiment shown in FIG. 1; FIG. 3 is a longitudinal cross-sectional view schematically showing the configuration of the modified example shown in FIG. 2 when the reflective surfaces of multiple movable reflectors are parallel to the wafer upper surface, and a graph showing the temperature distribution in the radial direction of the wafer upper surface in this case; FIG. 4 is a longitudinal cross-sectional view schematically showing the configuration of the modified example shown in FIG. 2 when the reflective surfaces of multiple movable reflectors are inclined with respect to the wafer upper surface to reflect IR light toward the center of the wafer, and a graph showing the temperature distribution in the radial direction of the wafer upper surface in this case; FIG. 5 is a graph showing an example of changes in the intensity (illuminance) of direct IR light and reflected IR light at positions on two IR lamps and a reflector and the wafer W below the two IR lamps and a reflector, with changes in the inclination angle of the reflector's reflective surface in the modified example shown in FIG. 6; FIG. 7 is a diagram schematically showing a model of the arrangement of IR lamp units used to calculate the example of changes in IR light intensity shown in FIG. 3 is a graph showing an example of the distribution of the intensity (illuminance) of IR light in the radial direction of the upper surface of the wafer when the angle of the reflector shown in FIG. 2 is tilted by a predetermined value.

[0014] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the accompanying drawings, in which: FIG.

[0015] 1 is a longitudinal cross-sectional view showing a schematic configuration of a wafer processing apparatus according to an embodiment of the present invention. The wafer processing apparatus 100 of this embodiment is broadly divided into a processing vessel whose interior can be depressurized, a gas supply unit connected to the upper part of the processing vessel for supplying processing gases for processing samples on substrates such as semiconductor wafers to be processed into the processing vessel, and an exhaust unit connected to the lower part of the processing vessel for exhausting gases inside the processing vessel. In the wafer processing apparatus 100, the processing vessel is a vacuum vessel connected to a transfer vessel (not shown) through whose internal space the samples to be processed are transferred. A sidewall of the processing vessel is provided with an opening (gate) (not shown) that serves as a passageway for the samples to pass between the interior of the transfer vessel and the interior of the processing vessel.

[0016] The processing vessel includes a vacuum vessel 1 having a processing chamber 5, which is a metallic vessel with a cylindrical space inside, and a sample stage 4, which is located at the bottom inside the processing chamber 5 and on whose upper surface a wafer W, which is a sample to be processed, is placed and held or supported. Also, a gas introduction unit 6 is located above the center of the processing chamber 5, and through which processing, dilution, or cleaning gases to be supplied to the processing chamber 5 flow in a pipe-like or cylindrical internal space. The gas introduction unit 6 is located above the center of the ceiling of the processing chamber 5, and its lower end may be exposed to the space inside the processing chamber 5, forming the ceiling of the processing chamber 5.

[0017] A dielectric, disk-shaped gas introduction plate 10 is disposed at the lower end of the gas introduction unit 6. At least one gas introduction port 11 is disposed at the center of the gas introduction plate 10, through which gases such as a processing gas that have passed through a cylindrical space inside the gas introduction unit 6 are introduced toward the processing chamber 5. In this example, particles of the processing gas that have entered the processing chamber 5 through the gas introduction port 11 diffuse inside the processing chamber 5 and adhere to a multi-layer film structure including a film layer to be processed and a mask film layer that are pre-arranged on the upper surface of the wafer W placed on the upper surface of the sample stage 4, and the adhered gas particles interact or react with the material on the surface of the film layer to be processed to form a desired product.

[0018] Furthermore, a lamp unit 2 is provided that constitutes the upper part of the vacuum vessel 1 and is disposed above the processing chamber 5 and surrounding the outer periphery of the gas introduction unit 6. The lamp unit 2 in this example is a lamp that can irradiate the interior of the processing chamber 5 with infrared light (IR light) to heat the wafer W placed on the upper surface of the sample stage 4, and has multiple (three in this figure) IR lamps 2a that are concentrically disposed around the outer periphery of the gas introduction unit 6. Furthermore, the lamp unit 2 is a flat, ring-shaped member made of a material that can transmit IR light, and is provided with a transmission window 2b that forms the ceiling of the processing chamber 5 around the lower end of the gas introduction unit 6.

[0019] Furthermore, the lamp unit 2 of this example is provided with a cover dome 3 above the IR lamp 2a, which is a plate-like member disposed to surround the outer periphery of the gas introduction unit 6 and cover the IR lamp 2a and the transmission window 2b, and which has a curved shape with a higher central portion and a lower peripheral portion. The cover dome 3 has a circular opening in the center and is ring-shaped when viewed from above, and its inner peripheral edge is disposed to surround the outer periphery of the gas introduction unit 6. Furthermore, the outer surface and lower surface (inner surface) of the cover dome 3 are inclined so that they become lower from the center toward the outer peripheral edge, and the angle of inclination increases from the center toward the outer periphery, giving it a so-called dome-like shape.

[0020] The inner surface of the cover dome 3 has such a shape and is configured to function as a reflective surface that reflects the IR light emitted from the IR lamps 2 a arranged in a ring shape. Therefore, at least a portion of the IR light emitted from the IR lamps 2 a arranged in a ring shape is reflected by the inner surface of the cover dome 3 toward the center and downward of the processing chamber 5. That is, in the example shown in the figure, the cover dome 3 is used as a reflective member for IR light, and the lower surface (inner surface) is used as a reflective surface. The IR light (reflected IR light) emitted from each IR lamp 2 a and reflected by the inner wall surface of the cover dome 3 in this manner travels downward toward the center of the upper surface of the stage 4, passes through the gaps between the multiple IR lamps 2 a arranged in a ring shape and the gap between the gas introduction unit 6, and is irradiated onto the surface of the wafer W near the center when the wafer W is placed above the upper surface of the sample stage 4.

[0021] That is, the IR light emitted upward from each IR lamp 2a is reflected by the inner surface of the cover dome 3, passes through a space closer to the center of the wafer W than each IR lamp 2a, and is irradiated onto the wafer W. As a result, in addition to the IR light (direct IR light) that arrives directly from the IR lamps 2a, the central region of the top surface of the wafer W is irradiated with more reflected IR light than the outer peripheral region, and thus IR light of greater intensity or amount is irradiated.

[0022] The lower part of the vacuum vessel 1 is connected to an exhaust section including an exhaust pump 16 and an exhaust pipe 13 connected thereto. In the exhaust section, one end of the exhaust pipe 13 is connected to the bottom surface of the vacuum vessel 1, and the inside of the exhaust pipe 13 is connected to the inside of the processing chamber 5 via an exhaust port 12 disposed below the sample stage 4 and facing the lower part of the processing chamber 5. In the exhaust section, a flow rate control valve 15 for controlling the flow rate or speed of the exhaust gas from the processing chamber 5 flowing through the exhaust pipe 13 is provided between the other end of the exhaust pipe 13 connected to the exhaust port 12 and the inlet of the exhaust pump 16, and the flow rate control valve 15 and the exhaust pump 16 are connected by an exhaust pipe 14.

[0023] The upper end of the gas introduction unit 6 is connected to a gas supply unit. The gas supply unit includes a plurality of gas storage units 9, such as tanks, in which gases are separated by type and stored therein; a gas supply line 7, which includes piping connected to each gas storage unit at one end and connected to the upper end of the gas introduction unit 6 at the other end, through which gas from the gas storage units flows; and a gas flow regulator 8, such as an MFC (mass flow controller), disposed on the gas supply line 7 between the gas storage unit 9 and the gas introduction unit 6, which regulates the flow rate or speed of the gas passing through. The pressure inside the processing chamber 5 is adjusted to a value within a range suitable for processing by balancing the flow rate per unit time of the gas introduced into the processing chamber 5 through the gas inlet 11 and the flow rate per unit time of particles, such as gas, discharged from the processing chamber 5 through the exhaust port 12.

[0024] A modified example of the embodiment of the present invention will be described with reference to Fig. 2. Fig. 2 is a longitudinal cross-sectional view schematically illustrating the configuration of a wafer processing apparatus according to a modified example of the embodiment shown in Fig. 1. The difference between the embodiment shown in Fig. 1 and the modified example shown in this figure is that the lamp unit 2 of the wafer processing apparatus 200 according to the modified example includes a plurality of reflector units 21, 22, and 23, each having a plurality of flat reflectors arranged in a concentric ring shape above each of the IR lamps 2a arranged in a concentric ring shape, and a cover dome 3' arranged on the outer periphery of the gas introduction unit 6, covering the reflector units 21 to 23, the IR lamps 2a, and the transmission window 2b above the reflector units 21 to 23, and having curved upper and lower surfaces that are higher in the center and lower in the outer periphery.

[0025] When viewed from above on a vertical axis (central axis) passing through the center of the wafer W or the circular sample stage 4, the reflector units 21, 22, and 23 of this example are each made up of a plurality of rectangular flat plate members, and each have a surface (reflective surface) capable of reflecting IR light, and are arranged in a ring shape on a circumference at three radial positions of different lengths from the center and at three different heights from the top surface of the wafer W. The surface (top surface) opposite to the reflective surface of each of the plurality of reflectors 21a, 21b, ..., 22a, 22b, ..., 23a, 23b, ... is connected to an angle adjustment mechanism arranged below (inside) the bottom surface of the cover dome 3', so that the reflective surface of IR light from the IR lamp 2a can be tilted toward the center of the processing chamber 5, the sample stage 4, or the wafer W.

[0026] In this example, the centers of the reflecting surfaces of the reflectors 21a, 21b, ..., 22a, 22b, ..., 23a, 23b, ... that make up each of the reflector units 21, 22, 23 as a plurality of groups are disposed at positions such that the radius from the central axis of the wafer W, stage 4, or processing chamber 5 for each reflector unit matches or approximates to the radius of each of the three IR lamps 2a arranged in a ring shape. Furthermore, the heights from the top surface of the wafer W at which the centers of the reflectors belonging to each of these three reflector units 21 to 23 are disposed increase for each group of reflectors as they approach the center of the processing chamber 5, sample stage 4, or wafer W. In other words, the centers of the reflectors 21a, 21b, ... are disposed at positions highest from the wafer W and are also disposed at the greatest vertical distance from the IR lamps 2a.

[0027] In this configuration, when the reflecting surfaces of the reflectors 21a, 21b, ..., 22a, 22b, ..., 23a, 23b, ... of the reflector units 21, 22, 23 are held at a predetermined inclination angle so that the reflected IR light (reflected IR light) is directed toward the center of the processing chamber 5, the stage 4, or the upper surface of the wafer W, the reflected IR light (reflected IR light) travels downward toward the center of the upper surface of the wafer W, passes through gaps between the IR lamps 2a arranged in a ring shape and gaps between the IR lamps 2a and the gas introduction unit 6, and is irradiated onto the upper surface of the wafer W. In other words, the IR light emitted upward from each IR lamp 2a is reflected by each reflector unit 21, 22, 23, passes through a space closer to the center of the wafer W than each IR lamp 2a, and is irradiated onto the wafer W. As a result, in the central region of the top surface of the wafer W, in addition to the IR light (direct IR light) that arrives directly from the IR lamp 2a, more IR reflected light is irradiated than in the outer peripheral region, and IR light of greater intensity is irradiated.

[0028] On the other hand, when the reflecting surface is held parallel to the upper surface of the wafer W, the upper surface of the wafer W is irradiated with both reflected IR light and direct IR light, as in the above case. However, the intensity of the reflected IR light irradiating the central region of the wafer W is relatively weaker than when the reflectors of the reflector units 21, 22, and 23 are tilted so that the reflected IR light is directed toward the center. Furthermore, in this example, the lower end of the gas introduction unit 6 forms the center of the ceiling of the processing chamber 5, and it is not possible to irradiate the wafer W with the high intensity obtained by arranging the IR lamps above the center and directing the IR light from the IR lamps 2a at an angle perpendicular to or close to the center with respect to the upper surface of the wafer W. Therefore, the intensity and amount of the direct IR light are also weaker than that irradiated toward the outer periphery.

[0029] 3 is a graph showing a schematic example of the temperature distribution on a wafer obtained when the reflecting surface of the reflector of the modified example shown in FIG. 2 is held parallel to the sample stage or wafer. In this figure, direct IR light is indicated by solid arrows, and reflected IR light is indicated by dashed arrows. As described above, in the example shown in this figure, direct IR light emitted downward from the lamp unit 2 is directly irradiated onto the upper surface of the wafer W arranged below by the IR lamp 2a. On the other hand, IR light emitted upward from the IR lamp 2a is reflected downward by the reflecting surface of the reflector of one of the reflector units 21 to 23, becomes reflected IR light, passes through the gaps between the three concentrically arranged ring-shaped IR lamps 2a, and is irradiated onto the upper surface of the wafer W below the gaps.

[0030] As described above, in the example shown in this figure, the intensity or amount of direct IR light and reflected IR light emitted from the lamp unit 2 is greater in the outer peripheral region than in the central region of the wafer W. As a result, the temperature distribution of the top surface of the wafer W is relatively low in the central region and high in the outer peripheral region.

[0031] FIG. 4 is a graph showing a schematic example of the temperature distribution on a wafer obtained when the reflecting surface of the reflector of the modified example shown in FIG. 2 is held facing the center of the sample stage or wafer. Note that in this figure, direct IR light is indicated by solid arrows and reflected IR light is indicated by dashed arrows. As described above, in the example shown in this figure, direct IR light emitted downward from the lamp unit 2 is directly irradiated onto the upper surface of the wafer W arranged below from the IR lamp 2a. On the other hand, IR light emitted upward from the IR lamp 2a is reflected downward and toward the center of the wafer W by the reflective surface of the reflector of one of the reflector units 21 to 23, becoming reflected IR light. This IR light passes through the gaps between the three concentrically arranged ring-shaped IR lamps 2a and is irradiated onto the upper surface of the wafer W below the gaps.

[0032] Furthermore, IR light emitted upward from the IR lamp 2 a-1 arranged at the innermost periphery is reflected downward by the reflectors 21 a, 21 b, ... toward the central region of the wafer W, and the reflected IR light passes through the gap between the innermost IR lamp 2 a-1 and the outer periphery of the lower end of the gas introduction unit 6, and further travels toward the center of the wafer W to be irradiated onto the upper surface of the wafer W. As described above, in addition to the configuration in which the transmission window 2 b is made of a material that is transmissive to IR light, the lower end of the cylindrical side wall of the gas introduction unit 6 or the gas introduction plate 10 may be made of a material that is transmissive to IR light. In this case, the reflected IR light reflected by at least one of the reflector units 21 to 23 passes through the gas introduction unit 6 that forms the center of the ceiling of the processing chamber 5 and is irradiated with a greater intensity or amount to the central portion of the wafer W, where the intensity or amount of direct IR light is small. As a result, the intensity or amount of IR reflected light is greater in the central region of the wafer W compared to the peripheral region, and the temperature of the top surface of the wafer W is relatively higher in the central region and lower in the peripheral region.

[0033] An example of the change in intensity (illuminance) of direct IR light and reflected IR light from the IR lamp 2a as a function of the inclination of the reflecting surface of the reflector of the lamp unit 2 in the modified example shown in Fig. 2 will be described using Fig. 5 and Fig. 6. Fig. 5 is a graph showing an example of the change in intensity (illuminance) of direct IR light and reflected IR light at positions on the wafer W below the two IR lamps and the reflector, as the inclination angle of the reflecting surface of the reflector changes in the modified example shown in Fig. 2. Fig. 6 is a graph showing an example of the distribution of IR light intensity (illuminance) in the radial direction of the upper surface of the wafer when the angle of the reflector shown in Fig. 2 is parallel to the wafer and when the angle of the reflecting surface of the reflector is inclined by a predetermined value.

[0034] 5 and 7, the change in the intensity of the IR light was calculated under conditions that were appropriately set as a model, including the arrangement and relative positional relationship between the lamp unit 2 and the wafer W. Fig. 6 is a diagram that schematically shows a model of the arrangement of the IR lamp unit used to calculate the example of the change in the intensity of IR light shown in Fig. 5.

[0035] In Figure 6, two IR lamps 2a-1 and 2a-2 are arranged above the wafer W at a height (distance) d1 above the upper surface of the wafer W (vertical direction in the figure), spaced apart by a distance L in the horizontal direction (horizontal direction in the figure). Also, reflectors 21a and 22a are arranged above the IR lamps 2a-1 and 2a-2, respectively, at a distance (height) d2. In this figure, the IR lamp 2a-1 on the left side of the figure is the innermost lamp in the radial direction from the center of the processing chamber 5 of the triple ring-shaped IR lamps 2a in Figure 2, and the IR lamp 2a-2 on the right side of the figure is the second lamp in the radial direction. The reflectors 21a and 22a located above these lamps belong to the reflector units 21 and 22, respectively.

[0036] With respect to the wafer W located below these IR lamps 2a-1, 2a-2 and reflectors 21a, 22a, the distance between points A and B on the wafer W projected vertically downward from above is defined as L. In this arrangement shown in the figure, the reflector 21a holds the reflecting surface parallel to the wafer W, and the reflector 22a tilts the reflecting surface at an angle θ relative to the horizontal direction (plane) while changing the angle within a predetermined range. The total intensity of the IR direct light from the IR lamps 2a-1, 2a-2 and the IR reflected light from the reflectors 21a, 22a is calculated at point (position) X where the IR reflected light, which is obtained by reflecting the IR direct light emitted directly upward from the IR lamp 2a-2 on the wafer W, is irradiated onto the wafer W.

[0037] In Figure 5, reference numeral 502 denotes the change in the total intensity of direct IR light from IR lamps 2a-1 and 2a-2, reference numeral 503 denotes the change in the total intensity of reflected IR light from reflectors 21a and 22a, and reference numeral 501 denotes the change in the sum of the total intensity of direct IR light 502 and the total intensity of reflected IR light 503. In the example shown in Figure 5, calculations were performed using an arbitrary unit of size: distance L = 5, height d1 = 5, and height d2 = 0.1. As the tilt angle of reflector 22a increases, position X moves away from position B, and the IR light intensity 501 at position X initially increases slightly and then decreases. In particular, the example shown in Figure 5 indicates that the IR light intensity 501 is maximized when position X is located between positions A and B in Figure 6 and the tilt angle of reflector 22a is small.

[0038] 7 shows the change in IR light intensity with respect to the change in distance from the center of the wafer W, when the IR lamp 2a and the reflector above it are disposed above a specific position in the radial direction from the center of the wafer W, and the angle of the reflecting surface is set to a predetermined value. In this figure, the IR lamp 2a is disposed at the distance position at the far right end of the graph, and reference numeral 602 indicates the change in the intensity of direct IR light from the IR lamp 2a, reference numeral 603 indicates the change in the intensity of reflected IR light from the reflector above the IR lamp 2a, and reference numeral 601 indicates the change in the sum of the intensity 602 of direct IR light and the intensity 603 of reflected IR light. It can be seen from this figure that the intensity 602 of direct IR light and the intensity 603 of reflected IR light increase as the radial position from the center of the wafer W approaches the point projected from above by the IR lamp 2a.

[0039] 1 and 2, the inventors have found that by using a cover dome 3 as a dome-shaped reflector and a plurality of reflector units 21 to 23 arranged in a ring shape along circumferences of different radii above each of the IR lamps 2a, it is possible to form a temperature distribution in which the temperature at the center of the wafer W is higher than that at the outer periphery. Furthermore, they have conceived the idea that by variably adjusting the angle of the reflecting surface of the reflector units 21 to 23 within a range of positive and negative angles, with 0° being the angle when the reflecting surface is parallel to the wafer W, the temperature value and distribution of the wafer W can be made as desired, including so-called center-high and outer-high temperatures.

[0040] In order to change the temperature distribution of the wafer W in this way, the angle adjustment mechanisms to which the reflectors of the reflector units 21 to 23 are attached have the function of changing the angle of the reflecting surface from facing the center or region near the center of the wafer W, stage 4, or processing chamber 5 to facing a region near the outer periphery of these, such as the inner peripheral sidewall of the processing chamber 5, and each of the reflector units 21 to 23 can be independently adjusted to a different angle. The angles of the reflector units 21 to 23 are detected by a control unit (not shown in FIGS. 1 and 2 ) that issues command signals to control the operation of each unit of the wafer processing apparatus 100, 200, receiving outputs from multiple temperature sensors arranged inside the stage 4, and are adjusted by sending signals to the angle adjustment mechanism depending on whether the temperature value or distribution of the wafer W is different from a target value.

[0041] As explained in the above embodiment and modified examples, in this embodiment and modified examples, the temperature values ​​and distribution of the wafer W during processing suitable for processing can be obtained by supplying a greater intensity or amount of reflected IR light from the lamp unit 2 to the center side of the wafer, or by irradiating the IR reflected light reflected by each reflector of the reflector units 21, 22, and 23 with the angle of the lamp unit 2 appropriately adjusted onto a desired region of the wafer W. This improves the processing accuracy and yield of wafers W processed in the wafer processing apparatuses 100 and 200.

[0042] DESCRIPTION OF SYMBOLS 1: Vacuum vessel, 2: Lamp unit, 2a: IR lamp, 2b: Transmission window, 3: Cover dome, 4: Sample stage, 5: Processing chamber, 6: Gas introduction unit, 7: Gas supply line, 8: Gas flow regulator, 9: Gas reservoir, 10: Gas introduction plate, 11: Gas introduction port, 12: Exhaust port, 13, 14: Exhaust pipe, 15: Flow rate control valve, 16: Exhaust pump, 21, 22, 23: Reflector unit, 21a, 21b, 22a, 22b, 23a, 23b: Reflector, 100, 200: Wafer processing apparatus

Claims

1. A wafer processing apparatus comprising: a processing chamber disposed within a vacuum vessel; a sample stage disposed in the lower center of the processing chamber on which a wafer to be processed is placed and supported; a gas inlet section disposed above the center of the upper surface of the sample stage and having a gas inlet port for introducing gas for processing the wafer into the processing chamber; and a lamp unit disposed around the gas inlet section and constituting the ceiling of the processing chamber, wherein the lamp unit comprises a plurality of ring-shaped lamps disposed in multiple layers around the gas inlet section and irradiating electromagnetic waves onto the wafer on the sample stage; and a reflecting member disposed in a ring shape above the plurality of lamps and around the gas inlet section and having a reflecting surface configured to reflect the electromagnetic waves radiated from the plurality of lamps downward and toward a region toward the center of the processing chamber, wherein the height of the reflecting surface is higher near the gas inlet section and becomes lower as it moves from the gas inlet section to the outer periphery.

2. A wafer processing apparatus according to claim 1, wherein the reflecting surface of the reflecting member is configured as a curved surface whose height decreases from the end on the central side toward the end on the outer periphery side.

3. A wafer processing apparatus as described in claim 1, wherein the lamp unit is provided with a plurality of flat reflectors arranged in a ring shape around the gas inlet section and the center of the sample stage when viewed from above, below the reflecting member, and the electromagnetic waves reflected by the plurality of reflectors are irradiated onto the wafer on the sample stage through gaps between the plurality of lamps or gaps between the lamps and the gas inlet section.

4. A wafer processing apparatus as described in claim 3, wherein the lamp unit is provided with a plurality of reflector units each consisting of a plurality of reflectors at a plurality of different radial positions around the center of the sample stage when viewed from above, around the gas inlet portion.

5. A wafer processing apparatus according to claim 4, wherein the plurality of reflector units each include a plurality of reflectors arranged at different heights from the upper surface of the sample stage.

6. A wafer processing apparatus as described in claim 3, comprising an angle variable mechanism for variably adjusting the angle at which each of the reflecting surfaces of the plurality of reflectors is tilted relative to a horizontal plane, the angle variable mechanism adjusting the tilt angle of each of the plurality of reflectors so as to reflect the electromagnetic waves toward the center or outer periphery of the sample stage.

7. A wafer processing apparatus as described in claim 4, comprising an angle variable mechanism for variably adjusting the angle at which each of the reflecting surfaces of the plurality of reflectors is tilted relative to a horizontal plane, the angle variable mechanism adjusting the tilt angle of each of the plurality of reflectors so as to reflect the electromagnetic waves toward the center or outer periphery of the sample stage.

8. A wafer processing apparatus as described in claim 5, comprising an angle variable mechanism for variably adjusting the angle at which each of the reflecting surfaces of the plurality of reflectors is inclined relative to a horizontal plane, the angle variable mechanism adjusting each angle of the plurality of reflectors so as to reflect the electromagnetic waves toward the center or outer periphery of the sample stage.

9. A wafer processing apparatus as claimed in any one of claims 6 to 8, comprising a function for realizing either a distribution in which the temperature of the wafer is lower in the central region and higher in the peripheral region, or a distribution in which the temperature of the wafer is higher in the central region and lower in the peripheral region, during processing of the wafer.

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