Wafer processing equipment

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

Technical Field

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

Background Art

[0002] In semiconductor devices, due to the requirements for lower power consumption and increased memory capacity, further miniaturization and three-dimensionalization of the device structure are progressing. In the manufacture of three-dimensional structured devices, since the structure is three-dimensional and complex, in addition to "vertical etching" that performs etching in a direction perpendicular to the conventional wafer surface, "isotropic etching" that enables etching in the lateral direction is required.

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

[0004] In this conventional technique, since thermal energy is applied to the surface of the object to be processed in the desorption step, a lamp that emits electromagnetic waves in the ultraviolet or infrared region is provided above the stage disposed in the processing chamber. In the desorption step, the object to be processed is heated to a temperature at which the reaction layer on the surface of the etched layer sublimes in a short time.

[0005] Furthermore, Japanese Patent Publication No. 2020-097060 (Patent Document 2) describes a conventional technology that includes a stage inside a processing chamber located within a vacuum vessel, and a ring-shaped IR lamp that irradiates infrared electromagnetic waves (hereinafter referred to as infrared light, IR, or IR light) arranged in multiple layers around a channel that supplies reactive particles such as radicals into the processing chamber directly above the stage, and a reflector positioned above these IR lamps that reflects the IR light emitted from the IR lamps toward the upper surface of the wafer stage in the processing chamber below or toward the wafer placed on that upper surface. With this configuration, the wafer is irradiated with IR light directly emitted from the IR lamps as well as IR light reflected by the reflector, and the wafer is heated in a short time. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2015-185594 [Patent Document 2] Japanese Patent Publication No. 2020-097060 [Overview of the Initiative] [Problems that the invention aims to solve]

[0007] As in the conventional technology described above, the reactive gas or vapor particles (etchant) supplied into the processing chamber inside the container are supplied downwards from an inlet located above the center of the upper surface of the sample stage, which is located in the center of the processing chamber and on which the wafer is placed and supported. The etchant adheres to the upper surface of the wafer and reacts with the surface of the film to be processed, which is a film structure comprising multiple film layers, including the film layer to be processed that is pre-placed on the upper surface of the wafer. The amount and magnitude distribution of this reaction on the upper surface of the wafer are greatly influenced, 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 surface, it is desirable to have a configuration in which etchant particles that reach the wafer move from the center of the wafer toward the outer periphery and are then exhausted from the space between the sample stage and the inner wall of the processing chamber surrounding it. Specifically, it is desirable to have a coaxial arrangement in which the gas inlet opening, the center of the wafer, and the vertical central axis of the ring-shaped space located on the outer periphery of the sample stage and surrounding the outer periphery wall of the sample stage coincide or approximate each other (coaxial exhaust). The above-mentioned conventional technology has this coaxial exhaust configuration.

[0009] On the other hand, in these conventional technologies, where an IR (infrared) lamp is used to heat the wafer, in order to ensure the heating rate and the accuracy of the resulting temperature distribution, it is necessary to irradiate the entire upper surface of the wafer with IR light of the desired intensity and amount. However, in the above conventional technologies, if the gas inlet is located above the center of the wafer, the IR lamp cannot be located directly above the center of the wafer, but must be located around the gas inlet. As a result, in such a configuration, the accuracy of adjusting the temperature of the central part of the wafer, or the temperature distribution of the wafer in the in-plane direction of the wafer, to the desired level may be compromised. This may lead to variations in the shape of the central region after etching and a relative decrease in accuracy compared to the outer peripheral part of the upper surface of the wafer.

[0010] The objective of the present invention is to provide a wafer processing apparatus that improves processing accuracy and yield. [Means for solving the problem]

[0011] The above problem is solved by a wafer processing apparatus comprising: a processing chamber disposed inside a vacuum vessel; a sample stage disposed in the lower central part of the processing chamber on which a wafer to be processed is placed and supported; a gas introduction section disposed above the central part of the upper surface of the sample stage and having a gas inlet for introducing gas for processing the wafer into the processing chamber; and a lamp unit disposed around the gas introduction section and constituting the top surface of the processing chamber, wherein the lamp unit comprises a plurality of ring-shaped lamps arranged in multiple layers around the gas introduction section to irradiate the wafer on the sample stage with electromagnetic waves; and a reflective member disposed in a ring shape above the plurality of lamps and around the gas introduction section and having a reflective surface configured to reflect electromagnetic waves emitted from the plurality of lamps downward and toward the central region of the processing chamber, wherein the height of the reflective surface is higher near the gas introduction section and decreases toward the outer periphery from the gas introduction section. [Effects of the Invention]

[0012] According to the present invention, electromagnetic waves emitted from a lamp are reflected upward in a predetermined direction, making it possible to change the temperature value and distribution of the wafer to a desired value. As a result, the temperature of the wafer during processing can be precisely kept within a range suitable for processing, improving the processing yield. [Brief explanation of the drawing]

[0013] [Figure 1] This is a schematic longitudinal cross-sectional view showing the general configuration of a wafer processing apparatus according to an embodiment of the present invention. [Figure 2] This is a schematic longitudinal cross-sectional view showing the configuration of a wafer processing apparatus according to a modified example of the embodiment shown in Figure 1. [Figure 3] Figure 2 shows a schematic longitudinal cross-sectional view illustrating the configuration in a modified example where the reflective surfaces of multiple movable reflectors are aligned parallel to the wafer surface, and a graph showing the temperature distribution in the radial direction of the wafer surface in this case. [Figure 4]Figure 2 shows a schematic cross-sectional view illustrating the configuration in which the reflective surfaces of multiple movable reflectors are tilted relative to the wafer surface to reflect IR light toward the center of the wafer, as well as a graph showing the temperature distribution in the radial direction of the wafer surface in this modified example. [Figure 5] Figure 2 shows a modified example in which the magnitude of the intensity (illuminance) of direct IR light and reflected IR light at the positions on the wafer W below the two IR lamps and the reflector changes with the change in the tilt angle of the reflector's reflective surface. [Figure 6] This figure schematically shows a model of the arrangement of IR lamp units used to calculate an example of the change in IR light intensity shown in Figure 5. [Figure 7] Figure 2 is a graph showing an example of the distribution of IR light intensity (illuminance) in the radial direction on the top surface of the wafer when the angle of the reflector shown is tilted by a predetermined value. [Modes for carrying out the invention]

[0014] Embodiments of the present invention will be described below with reference to the drawings. Hereinafter, examples and modifications of the present invention will be described with reference to Figures 1 to 7.

[0015] Figure 1 is a schematic longitudinal cross-sectional view showing the configuration of a wafer processing apparatus according to an embodiment of the present invention. The wafer processing apparatus 100 of this embodiment comprises, broadly speaking, a processing vessel whose interior can be depressurized, a gas supply unit connected to the upper part of the processing vessel and supplying a processing gas for processing a sample on a substrate such as a semiconductor wafer to be processed into the processing vessel, and an exhaust unit connected to the lower part of the processing vessel and exhausting the gas from inside the processing vessel. In the wafer processing apparatus 100, the processing vessel is connected to a transport vessel, which is a vacuum vessel (not shown) in which a sample to be processed is transported within the internal space, and the side wall of the processing vessel is provided with an opening (gate) (not shown) which serves as a passage for the sample to pass through inside between the inside of the transport vessel and the inside of the processing vessel.

[0016] The processing container is a vacuum container 1 made of metal and having a processing chamber 5 with a cylindrical space inside. It includes a sample stage 4 disposed below the interior of the processing chamber 5, on which a wafer W, which is a sample to be processed, is placed on its upper surface and held or supported. Also, above the central part of the processing chamber 5, a gas introduction unit 6 is arranged through which a processing gas, a dilution gas, or a cleaning gas supplied to the processing chamber 5 flows through the internal space in a pipe shape or a cylindrical shape. The gas introduction unit 6 may be arranged above the central part of the top surface of the processing chamber 5, and its lower end part may be exposed into the space inside the processing chamber 5 to form the top surface of the processing chamber 5.

[0017] At the lower end part of the gas introduction unit 6, a gas introduction plate 10 having a disc shape made of a dielectric is arranged. At the central part of the gas introduction plate 10, at least one gas introduction port 11 is arranged through which a gas such as a processing gas passing through the cylindrical space inside the gas introduction unit 6 is introduced inward and directed toward the processing chamber 5. In this example, the particles of the processing gas that enter the processing chamber 5 through the gas introduction port 11 diffuse inside the processing chamber 5 and adhere onto a film structure having a plurality of layers including a film layer to be processed and a mask film layer pre-arranged on the upper surface of the wafer W placed on the upper surface of the sample stage 4. The particles of the attached gas and the material on the surface of the film layer to be processed interact or react to form a desired product.

[0018] Furthermore, a lamp unit 2 is provided which constitutes the upper part of the vacuum container 1 and is arranged 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 capable of irradiating infrared light (IR light) inside the processing chamber 5 to heat the wafer W placed on the upper surface of the sample stage 4, and has IR lamps 2a arranged in multiple (triple in this figure) concentric shapes surrounding the outer periphery of the gas introduction unit 6. Further, the lamp unit 2 is a flat ring-shaped member composed of a member through which IR light can pass, and includes a transmission window 2b that forms the top surface of the processing chamber 5 around the lower end part of the gas introduction unit 6.

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

[0020] The inner surface of the cover dome 3 has such a shape and is configured so that the inner surface can act as a reflecting surface that reflects the IR light radiated from the IR lamp 2a. Thus, at least a part of the IR light irradiated from the IR lamps 2a arranged in a ring shape is reflected by the inner surface of the cover dome 3 toward the center and below of the processing chamber 5. That is, in the example of this figure, the cover dome 3 serves as a reflecting member for IR light, and the lower surface (inner surface) is used as the reflecting surface. In this way, the IR light (IR reflected light) radiated from each IR lamp 2a and reflected by the inner wall surface of the cover dome 3 travels downward and toward the center of the upper surface of the stage 4, passes through the gaps between the IR lamps 2a arranged in multiple ring shapes and the gap between the gas introduction unit 6, and when the wafer W is placed above the upper surface of the sample stage 4, it is irradiated onto the central side surface of the wafer W.

[0021] That is, the IR light radiated upward from each IR lamp 2a is reflected by the inner surface of the cover dome 3, passes through the space closer to the center of the wafer W than each IR lamp 2a, and irradiates the wafer W. As a result, in the region on the center side of the upper surface of the wafer W, in addition to the IR light (IR direct light) that directly reaches from the IR lamp 2a, more IR reflected light is irradiated than in the region on the outer peripheral side, and a larger intensity or amount of IR light is irradiated.

[0022] The lower part of the vacuum vessel 1 is connected to an exhaust section which includes 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 in communication with the inside of the processing chamber 5 via an exhaust port 12 located below the sample stage 4 and facing the lower part of the processing chamber 5. The exhaust section is equipped with a flow control valve 15 between the other end of the exhaust pipe 13 connected to the exhaust port 12 and the inlet of the exhaust pump 16, which adjusts the flow rate or velocity of the exhaust gas flowing from the processing chamber 5 inside the exhaust pipe 13, and the flow 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 the gas supply unit. The gas supply unit includes multiple gas storage units 9, such as tanks, in which each type of gas is separated and stored inside; a gas supply line 7, which includes piping through which gas from the gas storage units flows, with one end connected to each gas storage unit and the other end connected to the upper end of the gas introduction unit 6; and a gas flow regulator 8, such as an MFC (mass flow controller), which is positioned on the gas supply line 7 between the gas storage units 9 and the gas introduction unit 6 to adjust the flow rate or velocity of the flowing gas. 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 gas introduced into the processing chamber 5 from the gas inlet 11 and the flow rate per unit time of gas and other particles discharged from the processing chamber 5 through the exhaust port 12.

[0024] A modified example of the embodiment of the present invention will be explained using Figure 2. Figure 2 is a schematic longitudinal cross-sectional view showing the configuration of a wafer processing apparatus according to a modified example of the embodiment shown in Figure 1. The difference between the embodiment shown in Figure 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 comprises a plurality of reflector units 21, 22, and 23, each having a plurality of flat plate shapes in which reflectors are arranged in a plurality of concentric ring shapes above each of the IR lamps 2a arranged in a plurality of concentric ring shapes, and a cover dome 3' which is located on the outer periphery of the gas introduction unit 6 and covers the reflector units 21 to 23, the IR lamps 2a, and the transmissive window 2b above the reflector units 21 to 23, and has curved upper and lower surfaces with a higher central part and a lower outer periphery.

[0025] In this example, the reflector units 21, 22, and 23 are each composed of multiple rectangular flat plate members, and when viewed from above on a vertical axis (central axis) passing through the center of the wafer W or the sample stage 4 which has a circular surface, they are arranged in a ring shape on a circumference at three different radial positions of different lengths radially from the center, and each reflector is 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 multiple reflectors 21a, 21b, ..., 22a, 22b, ..., 23a, 23b, ... is connected to an angle adjustment mechanism located on the underside (inside) of the bottom surface of the cover dome 3', thereby enabling the reflective surface of the IR light from the IR lamp 2a to be tilted toward the center of the processing chamber 5, the sample stage 4, or the wafer W.

[0026] In this example, the reflective surfaces of the reflectors 21a, 21b, ..., 22a, 22b, ..., 23a, 23b, ..., each of the reflector units 21, 22, 23, are arranged as multiple sets of reflectors 21a, 21b, ..., 22a, 22b, ..., 23a, 23b, ..., and for each reflector unit, the center of the reflector surface is positioned such that the radius from the central axis of the wafer W, stage 4, or processing chamber 5 matches or is considered to match the radius of each of the three ring-shaped IR lamps 2a. Furthermore, the height from the top surface of the wafer W to where the center of the reflector surface of each of these three reflector units 21 to 23 is located increases for each set of reflectors as it approaches the processing chamber 5, sample stage 4, or the center of the wafer W. That is, the center of the reflectors 21a, 21b, ... is positioned at the highest position from the wafer W, and the vertical distance from the IR lamps 2a is also the largest.

[0027] In this configuration, when the reflective surfaces of the reflectors 21a, 21b, ..., 22a, 22b, ..., 23a, 23b, ... of each reflector unit 21, 22, 23 are tilted and held at a predetermined angle so that the reflected IR light (IR reflected light) is directed toward the processing chamber 5 or the stage 4 and the center of the wafer W, the reflected IR light (IR reflected light) travels downward toward the center of the wafer W, passes through the gaps between the multiple ring-shaped IR lamps 2a and the gaps between them and the gas introduction unit 6, and irradiates the wafer W. That is, the IR light emitted upward from each IR lamp 2a is reflected by each reflector unit 21, 22, 23, passes through the space closer to the center of the wafer W than each IR lamp 2a, and irradiates the wafer W. As a result, in the central region of the upper surface of the wafer W, in addition to the IR light (direct IR light) that directly reaches from the IR lamp 2a, more IR reflected light is irradiated than in the outer peripheral region, resulting in irradiation with a higher intensity of IR light.

[0028] On the other hand, if the reflective surface is held parallel to the upper surface of the wafer W, then, as in the case described above, the upper surface of the wafer W is irradiated with both IR reflected light and IR direct light. However, compared to the case where the reflectors of each reflector unit 21, 22, and 23 are tilted so that the IR reflected light is directed towards the center, the intensity of the IR reflected light irradiated to the central region of the wafer W is relatively smaller. Furthermore, in this example, the lower end of the gas introduction unit 6 constitutes the central part of the top surface of the processing chamber 5, and it is not possible to place the IR lamp above the center and irradiate the upper surface of the wafer W with the strong intensity obtained by incidenting the IR direct light from the IR lamp 2a at an angle perpendicular or close to perpendicular to the upper surface of the wafer W. For this reason, the intensity and amount of IR direct light are also relatively smaller compared to those irradiated to the outer periphery.

[0029] Figure 3 is a schematic graph showing an example of the temperature distribution on a wafer obtained when the reflective surface of the modified reflector shown in Figure 2 is held parallel to the sample stage or wafer. In this figure, direct IR light is shown by solid arrows, and reflected IR light is shown by dashed arrows. As described above, in the example shown in this figure, the direct IR light emitted downward from the lamp unit 2 is directly irradiated onto the upper surface of the wafer W positioned below the IR lamp 2a. On the other hand, the IR light emitted upward from the IR lamp 2a is reflected downward by the reflective surface 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 irradiates 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 region of the wafer W compared to the central region. Therefore, the temperature of the top surface of the wafer W is relatively lower in the central region and higher in the outer region.

[0031] Figure 4 is a schematic graph showing an example of the temperature distribution on a wafer obtained when the reflective surface of the modified reflector shown in Figure 2 is held facing the sample stage or the center of the wafer. In this figure as well, direct IR light is shown by solid arrows and reflected IR light is shown 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 positioned below 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 one of the reflector units 21 to 23, becoming reflected IR light that passes through the gaps between the three concentrically arranged ring-shaped IR lamps 2a and irradiates the upper surface of the wafer W below the gaps.

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

[0033] Using Figures 5 and 6, we will explain an example of the change in the magnitude of the intensity (illuminance) of the direct IR light and IR reflected light from the IR lamp 2a in the modified example shown in Figure 2, based on the degree of inclination of the reflective surface of the lamp unit 2. Figure 5 is a graph showing an example of the change in the magnitude of the intensity (illuminance) of the direct IR light and IR reflected light at the two IR lamps and the reflector and the position on the wafer W below them, in the modified example shown in Figure 2, as a result of changing the inclination angle of the reflective surface of the reflector. Figure 6 is a graph showing an example of the distribution of IR light intensity (illuminance) in the radial direction on the upper surface of the wafer, when the angle of the reflector shown in Figure 2 is parallel to the wafer and when the angle of the reflective surface of the reflector is inclined by a predetermined value.

[0034] In Figures 5 and 7, a model was used in which the conditions, including the arrangement and relative positional relationship between the lamp unit 2 and the wafer W, were appropriately set, and the change in the intensity of the IR light described above was calculated under these conditions. Figure 6 is a schematic diagram showing a model of the arrangement of the IR lamp unit used to calculate an example of the change in the intensity of the IR light shown in Figure 5.

[0035] In Figure 6, two IR lamps 2a-1 and 2a-2 are positioned at a height (distance) d1 above the top surface of the wafer W, separated by a distance L in the horizontal direction (left-right direction). Above each of these IR lamps 2a-1 and 2a-2, reflectors 21a and 22a are positioned at a distance (distance) d2 apart. In this figure, the IR lamp 2a-1 on the left is the innermost of the three ring-shaped IR lamps 2a in Figure 2, radially from the center of the processing chamber 5, and the IR lamp 2a-2 on the right is the second in that radial direction. The reflectors 21a and 22a located above these belong to 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, let L be the distance between points A and B on the wafer W projected vertically downward from above. In this arrangement shown in the figure, the reflector 21a holds its reflective surface parallel to the wafer W, and the reflector 22a changes the angle θ at which its reflective surface is tilted relative to the horizontal direction (surface) within a predetermined range. The total intensity of the IR direct light from IR lamps 2a-1, 2a-2 and the IR reflected light from reflectors 21a, 22a at point X where the IR direct light emitted directly upward from IR lamp 2a-2 is reflected by reflector 22a and irradiated onto the wafer W is calculated.

[0037] In Figure 5, the symbol 502 represents the change in the total intensity of direct IR light from IR lamps 2a-1 and 2a-2, the symbol 503 represents the change in the total intensity of reflected IR light from reflectors 21a and 22a, and the symbol 501 represents the change in the sum of the total intensity of direct IR light 502 and the total intensity of reflected IR light 503. In this example, the calculations were performed using a distance L of 5, a height d1 of 5, and a height d2 of 0.1 as units of arbitrary size. It is shown that as the tilt angle of reflector 22a increases, position X moves away from position B, and the intensity of IR light 501 at position X initially increases slightly before decreasing. In particular, in this example, it is shown that the intensity of IR light 501 is maximum when the tilt angle of reflector 22a is small, with position X located between positions A and B in Figure 6.

[0038] Figure 7 shows the change in IR light intensity with respect to a change in distance from the center of the wafer W, when an IR lamp 2a and a reflector above it are placed above a specific position radially 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 placed at the distance to the right end of the graph, reference numeral 602 indicates the change in the intensity of the direct IR light from the IR lamp 2a, reference numeral 603 indicates the change in the intensity of the reflected IR light from the reflector above the IR lamp 2a, and reference numeral 601 indicates the change in the sum of the intensities of the direct IR light intensity 602 and the reflected IR light intensity 603. In this figure, it can be seen that as the radial position from the center of the wafer W approaches the projection point from above the IR lamp 2a, the intensities of the direct IR light intensity 602 and the reflected IR light intensity 603 increase.

[0039] Based on the results of the above-mentioned studies, the inventors have found that, in the embodiments and modifications shown in Figures 1 and 2, by using a plurality of reflector units 21 to 23 arranged in a ring shape along the circumference of circles of different radii above the cover dome 3 and IR lamp 2a, respectively, which are dome-shaped reflectors, it is possible to create a temperature distribution in the central part of the wafer W that is higher than that in the outer peripheral region. Furthermore, the inventors have conceived of adjusting the angle of the reflector surfaces of the reflector units 21 to 23 within a range of positive and negative values, with the state parallel to the wafer W being 0°, so the temperature value and distribution of the wafer W can be made to a desired level, including so-called high temperature in the middle and high temperature on the outer edge.

[0040] In order to change the temperature distribution of the wafer W in this way, the angle adjustment mechanism to which each reflector in the reflector units 21 to 23 is attached has the function of changing the angle from one in which the reflective surface is directed toward the center or central region of the wafer W, stage 4, or processing chamber 5, to one in which it is directed toward the outer periphery, for example, the inner side wall 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 these reflector units 21 to 23 are detected by a control unit that sends command signals to adjust the operation of various parts of the wafer processing apparatus 100, 200 (not shown in Figures 1 and 2) by receiving outputs from a plurality of temperature sensors located inside the stage 4, and adjusting them by sending a signal to the angle adjustment mechanism according to the temperature value or distribution of the wafer W and the target.

[0041] As described in the above embodiments and modifications, in these embodiments and modifications, by supplying a greater intensity or amount of IR reflected light from the lamp unit 2 to the center side of the wafer, or by irradiating a desired region of the wafer W with IR reflected light reflected by each reflector unit 21, 22, 23, whose angles of the lamp unit 2 are appropriately adjusted, a suitable temperature value and distribution of the wafer W during processing can be obtained. This improves the accuracy and yield of the wafer W processed by the wafer processing apparatus 100, 200. [Explanation of symbols]

[0042] 1...Vacuum chamber, 2...Lamp unit, 2a...IR lamp, 2b...Transmission window, 3...Covered dome, 4...Sample stage, 5...Processing chamber, 6...Gas introduction unit, 7...Gas supply line, 8...Gas flow regulator, 9...Gas storage section, 10...Gas introduction plate, 11...Gas inlet, 12...Exhaust port, 13,14...Exhaust pipe, 15...Flow control valve, 16...Exhaust pump, 21,22,23...Reflector unit, 21a,21b,22a,22b,23a,23b...Reflector, 100,200...Wafer processing equipment.

Claims

1. The device comprises a processing chamber located inside a vacuum vessel, a sample stage located in the lower central part of the processing chamber on which a wafer to be processed is placed and supported, a gas introduction section located above the central part of the upper surface of the sample stage and having a gas inlet for introducing gas for processing the wafer into the processing chamber, and a lamp unit located around the gas introduction section and forming the top surface of the processing chamber. The lamp unit comprises a plurality of ring-shaped lamps arranged in multiple layers around the gas introduction section to irradiate the wafer on the sample stage with electromagnetic waves, and a reflective member having a reflective surface arranged in a ring shape above the plurality of lamps around the gas introduction section and configured to reflect the electromagnetic waves emitted from the plurality of lamps downward toward the central region of the processing chamber, wherein the height of the reflective surface is higher near the gas introduction section and decreases toward the outer periphery from the gas introduction section. The lamp unit comprises a plurality of flat reflectors arranged in a ring shape around the gas introduction section and around the center of the sample stage when viewed from above, on the lower side of the reflector member, and the electromagnetic waves reflected by the plurality of reflectors are irradiated onto the wafer on the sample stage through the gaps between the plurality of lamps or the gap between the lamps and the gas introduction section.

2. A wafer processing apparatus according to claim 1, A wafer processing apparatus in which the reflective surface of the reflective member is a curved surface whose height decreases from the central end to the outer peripheral end.

3. A wafer processing apparatus according to claim 1, The lamp unit comprises a plurality of reflector units, each consisting of a plurality of reflectors, located around the gas introduction section and, when viewed from above, around the center of the sample stage at a plurality of different radial positions from the center.

4. A wafer processing apparatus according to claim 3, The plurality of reflector units are wafer processing apparatuses each equipped with a plurality of reflectors that make up each unit, each at a different height from the top surface of the sample stage.

5. A wafer processing apparatus according to claim 1, A wafer processing apparatus comprising an angle variable mechanism for variably adjusting the angle at which each of the multiple reflectors' reflective surfaces is inclined with respect to a horizontal plane, wherein the angle variable mechanism adjusts the inclination angle of each of the multiple reflectors so as to reflect the electromagnetic waves toward the center or outer periphery of the sample stage.

6. A wafer processing apparatus according to claim 3, A wafer processing apparatus comprising an angle variable mechanism for variably adjusting the angle at which each of the multiple reflectors' reflective surfaces is inclined with respect to a horizontal plane, wherein the angle variable mechanism adjusts the inclination angle of each of the multiple reflectors so as to reflect the electromagnetic waves toward the center or outer periphery of the sample stage.

7. A wafer processing apparatus according to claim 4, A wafer processing apparatus comprising an angle variable mechanism for variably adjusting the angle at which each of the plurality of reflectors' reflective surfaces is inclined with respect to a horizontal plane, wherein the angle variable mechanism adjusts the angles 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 according to any one of claims 5 to 7, A wafer processing apparatus equipped with the function to achieve either a temperature distribution in which the central region is low and the outer region is high, or a temperature distribution in which the central region is high and the outer region is low, during the processing of the wafer.

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