JP2011061654A - Dry etching method for substrate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide the dry etching method of a substrate efficiently and stably achieving micro-fine working to a substrate made of hard and brittle materials with high hardness and brittleness such as a crystal substrate. <P>SOLUTION: This dry etching method of a substrate comprises the process of: adhering a crystal substrate 8 to a support substrate 7 on which an adhesive film 7b which is dissolvable by wet etching is preliminarily formed on a dissolvable resin substrate 7a by wet etching; placing the crystal substrate 8 in a dry etching device 4 with such an attitude that the working face is turned upward to hold it by electrostatic suction; supplying heat transmission gas for cooling between the substrate placing place and the support substrate; making a plasma generation source generate plasma to etch the working face of the substrate; making a wet etching device 5 dissolve the support substrate 7 to separate and extract only the crystal substrate 8. Thus, the crystal substrate 8 and the support substrate 7 are highly efficiently separated. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a dry etching method suitable for processing a substrate made of a hard and brittle material such as a quartz substrate.

  Wet etching is employed as a method for processing a quartz substrate in order to manufacture a quartz crystal device such as a quartz crystal vibrating piece. However, the processing width that can be realized by wet etching of the quartz substrate is about 100 to 80 μm, and there is a limit to miniaturization. Further, in wet etching, the quartz substrate is etched along the crystal orientation, which becomes a processing restriction.

  In order to solve the limit of miniaturization and processing restrictions that are unavoidable in wet etching, it has been proposed to process a quartz substrate by dry etching. For example, Patent Documents 1 and 2 disclose a method of manufacturing a quartz crystal resonator element from a quartz substrate by using dry etching and wet etching together. Patent Document 3 discloses a method of manufacturing a crystal vibrating piece from a crystal substrate only by dry etching.

JP 2007-13383 A JP 2007-259036 A JP 2007-166242 A

  However, a dry etching method that can be practically used in consideration of the characteristics of a quartz substrate that is a hard and brittle material having high hardness, including those disclosed in Patent Documents 1 to 3, has not been proposed. That is, it is possible to experimentally finely process a crystal piece or the like by a general dry etching method. For example, the diameter or one side is about 2 to 3 inches, and the thickness is about 100 to 200 μm or less. There has not yet been provided a practical dry etching method capable of efficiently and stably realizing fine processing on a quartz substrate that is very thin and brittle and is likely to be warped or cracked due to heat.

  Therefore, an object of the present invention is to provide a dry etching method for a substrate that can efficiently and stably realize microfabrication of a substrate made of a hard and brittle material such as a quartz substrate.

The substrate dry etching method of the present invention includes a vacuum container to which an etching gas is supplied, a plasma generation source for generating plasma by ionizing the etching gas in the vacuum container, and a substrate disposed in the vacuum container. A substrate placement unit on which the substrate is placed, an electrostatic adsorption electrode built in the substrate placement unit, and a heat transfer gas is supplied to the substrate placement surface on which the substrate is placed on the substrate placement unit A dry etching method for performing an etching process on at least one surface set as a processing surface of two surfaces forming the front and back surfaces of the substrate by a dry etching apparatus including a heat transfer gas supply mechanism. A substrate prep for preparing a support substrate made of a material that can be dissolved by wet etching, and having a pressure-sensitive adhesive layer that can be dissolved by wet etching on one side. A substrate laminating step of laminating the back surface of the processed surface of the substrate to the adhesive layer of the support substrate; and the substrate having the support substrate bonded to the back surface of the processed surface is a vacuum container of the dry etching apparatus. A substrate carrying-in step in which the substrate is placed on the substrate placement surface with the processing surface of the substrate facing upward, and a DC voltage is applied to the electrostatic chucking electrode to support the substrate. A substrate adsorption holding step of electrostatically adsorbing and holding the substrate mounting surface, and supplying the heat transfer gas between the substrate mounting surface and the support substrate by the heat transfer gas supply mechanism, An etching step in which plasma is generated by a plasma generation source to etch a processed surface of the substrate; and the substrate is lifted from the substrate mounting surface together with the support substrate after the etching step is completed. Comprising a substrate carry-out step of al unloaded, and a substrate isolation step of removing the support substrate by separating only the substrate by dissolving by wet etching with the adhesive layer.

  According to the present invention, a substrate to be processed is bonded to a support substrate, which is made of a material that can be dissolved by wet etching, and in which a pressure-sensitive adhesive layer that can be dissolved by wet etching is formed in advance on one side, and the substrate is bonded to the substrate. Is placed on the substrate plate mounting surface in a posture with the processing surface facing upward, and plasma is supplied while supplying a heat transfer gas for cooling between the substrate mounting surface and the support substrate while being held by electrostatic adsorption. After etching the processed surface of the substrate by generating plasma from the generation source, the support substrate is dissolved together with the adhesive layer by wet etching, and only the substrate is separated and taken out, so that it can be handled during loading and unloading etc. In addition to preventing damage to the substrate, the substrate is cooled with high efficiency and high accuracy to prevent damage such as warping, peeling, and cracking of the substrate due to heat and deterioration of the material. The separation between the substrate and the resin substrate can be performed with high efficiency can be realized fine processing to the substrate made of a brittle hard and brittle material with high hardness such as a crystal substrate efficiently and stably in the.

The block diagram which shows the crystal device manufacturing system of Embodiment 1 of this invention Process explanatory drawing of the crystal device manufacturing method of Embodiment 1 of this invention Structure explanatory drawing of the crystal oscillator manufactured by the crystal device manufacturing system of Embodiment 1 of the present invention Structure explanatory drawing of the crystal substrate used for the crystal device manufacturing system of Embodiment 1 of this invention Process explanatory drawing of the bonding process of the resin substrate and crystal substrate in the crystal device manufacturing method of Embodiment 1 of this invention Process explanatory drawing of the sticking process of the resin substrate and the adhesive film in the crystal device manufacturing method of Embodiment 1 of this invention. Process explanatory drawing of the sticking process of the resin substrate and the adhesive film in the crystal device manufacturing method of Embodiment 1 of this invention. Process explanatory drawing of the bonding process of the resin substrate and crystal substrate in the crystal device manufacturing method of Embodiment 1 of this invention Structure explanatory drawing of the dry etching apparatus used in the crystal device manufacturing method of Embodiment 1 of this invention Operation | movement explanatory drawing of the dry etching apparatus used in the crystal device manufacturing method of Embodiment 1 of this invention Operation | movement explanatory drawing of the dry etching apparatus used in the crystal device manufacturing method of Embodiment 1 of this invention Process explanatory drawing of the dry etching method of the board | substrate in the crystal device manufacturing method of Embodiment 1 of this invention Process explanatory drawing of the dry etching method of the board | substrate in the crystal device manufacturing method of Embodiment 1 of this invention Process explanatory drawing of the dry etching method of the board | substrate in the crystal device manufacturing method of Embodiment 1 of this invention Process explanatory drawing of the dry etching method of the board | substrate in the crystal device manufacturing method of Embodiment 1 of this invention Process explanatory drawing of the dry etching method of the board | substrate in the crystal device manufacturing method of Embodiment 1 of this invention Process explanatory drawing of the dry etching method of the board | substrate in the crystal device manufacturing method of Embodiment 1 of this invention Process explanatory drawing of the dry etching method of the board | substrate in the crystal device manufacturing method of Embodiment 1 of this invention Explanatory drawing of the electrostatic adsorption of the board | substrate in the dry etching method of the board | substrate of Embodiment 1 of this invention Explanatory drawing of the board | substrate holding | maintenance method and board | substrate mounting method in the dry etching method of the board | substrate of Embodiment 1 of this invention Explanatory drawing of the board | substrate holding | maintenance method and board | substrate mounting method in the dry etching method of the board | substrate of Embodiment 1 of this invention Explanatory drawing of the board | substrate holding | maintenance method and board | substrate mounting method in the dry etching method of the board | substrate of Embodiment 1 of this invention Block diagram showing a crystal device manufacturing system according to a second embodiment of the present invention. Process explanatory drawing of the crystal device manufacturing method of Embodiment 2 of this invention Process explanatory drawing of the bonding process of the resin substrate and crystal substrate in the crystal device manufacturing method of Embodiment 2 of this invention Process explanatory drawing of the bonding process of the resin substrate and crystal substrate in the crystal device manufacturing method of Embodiment 2 of this invention

  Next, embodiments of the present invention will be described with reference to the drawings. Since quartz is high in hardness and brittle, the quartz substrate has characteristics different from those of general processing objects such as a semiconductor substrate in performing fine processing by dry etching. Specifically, a quartz substrate used for manufacturing a quartz crystal device such as a quartz resonator is very thin and brittle with a diameter or a side of about 2 to 3 inches and a thickness of about 100 to 200 μm or less. Therefore, handling such as carrying in and out of the vacuum chamber of the dry etching apparatus is difficult. In addition, since the quartz substrate is very hard and has a slow etching rate, during dry etching, the quartz substrate is exposed to heat from plasma for a long time and becomes high temperature. As described above, a very thin and brittle quartz substrate having a thickness of about 100 to 200 μm is liable to be warped by heat and cracks caused by it. In addition, the crystal itself is altered by the high temperature during dry etching. Specifically, the crystal itself is altered at a high temperature of about 400 to 500 ° C. or more. Therefore, sufficient measures against heat are necessary in dry etching of a quartz substrate. The embodiment of the present invention described below realizes stable and highly efficient microfabrication by dry etching of a quartz substrate by considering the above points.

(Embodiment 1)
First, the configuration of the crystal device manufacturing system 1 and the outline of the manufacturing process of the crystal resonator will be described with reference to FIGS. The crystal device manufacturing system 1 includes a vacuum bonding apparatus 2, a vacuum bonding apparatus 3, a dry etching apparatus 4, a wet etching apparatus 5, and a cleaning apparatus 6. The crystal device manufacturing system 1 has a function of manufacturing a plurality of crystal resonators 9 from the crystal substrate 8 by sequentially dry-etching the crystal substrate 8 (substrate) on which the support substrate 7 is bonded and supported from both the front and back surfaces. Have. In FIG. 1, a solid line and a broken line indicating processing paths correspond to processing processes (process A and process B shown in FIG. 2) for the front and back surfaces of the quartz substrate 8, respectively.

In the process A, first, the pressure-sensitive adhesive layer 7b is attached to the resin substrate 7a by the vacuum applicator 2 (ST1A), and the support substrate 7 for supporting the crystal substrate 8 is prepared. The resin substrate 7a
Polyethylene terephthalate (PET) is molded into a sheet shape, and the adhesive film 7b is a polyimide-based adhesive film having a constant thickness, both of which are made of a resin that can be dissolved by wet etching with a chemical solution. Become. Next, the back side of the quartz substrate 8 is vacuum bonded to the support substrate 7 via the adhesive film 7b and supported by the vacuum laminating device 3 (ST2A), and is carried into the dry etching device 4 to be brought into the surface side of the quartz substrate 8 Is dry-etched (ST3A).

  Thereafter, the support substrate 7 is dissolved and removed (wet etching) from the quartz substrate 8 by the wet etching apparatus 5 (ST4A). Next, the quartz crystal substrate 8 is sent to the cleaning device 6 and subjected to the cleaning process of the chemical solution, and then becomes the target of the process B. That is, (ST1B) to (ST4B) similar to the above (ST1A) to (ST4A) are executed for the back surface of the quartz substrate 8. And it is sent to the washing | cleaning apparatus 6 again, and the chemical | medical solution washing process is performed. Through the above process, the quartz substrate 8 is finely processed by dry etching, and the quartz resonator 9 is formed.

  Next, with reference to FIG. 3, the structure of the crystal unit 9 manufactured by the above process will be described. As shown in FIG. 3A, the crystal resonator 9 has a shape in which a pair of rectangular cross-section arm portions 9b are extended from one side of a flat rectangular parallelepiped base portion 9a. Grooves 9c and 9d having a rectangular and bottomed cross-sectional shape are provided on both surfaces (upper and lower surfaces in FIG. 3B) of each arm portion 9b. Further, the mask layers 10a and 10b remain on both surfaces of the base portion 9a and the arm portion 9b. These mask layers 10a and 10b constitute device pattern portions 10Pa and 10Pb used as mask pattern layers for forming the shape of the crystal resonator 9 in dry etching described later. These mask layers 10a and 10b may be used as electrodes for vibrating the crystal unit 9, or may be removed in a later step to form another electrode on the crystal unit 9.

  The dimensions of the crystal unit 9 are not particularly limited, but are set as follows, for example. The thickness T1 (excluding mask layers 10a and 10b) of the base portion 9a and the arm portion 9b is about 100 μm. The width W1 of the base 9a is about 200 to 500 μm, and the width W2 of the arm 9b is about 60 to 120 μm. The grooves 9c and 9d have a depth D1 of about 40 μm and a width W3 of about 20 to 30 μm. The thickness T2 of the mask layers 10a and 10b is about 3 to 5 μm.

  Next, the configuration of the quartz substrate 8 will be described with reference to FIG. In FIG. 4A, the quartz substrate 8 has a thin disk shape with a thickness of about 100 μm and a diameter of about 2 to 3 inches, and has an outer shape having an orientation flat 8a with one end cut off. The following mask layers 10a and 10b are formed on the front surface 8c and the back surface 8d of the quartz substrate 8 in a plan view. Annular frame portions 10Ea and 10Eb are formed on the front and back of the peripheral portion of the quartz substrate 8, and cross frame portions 10Ca and 10Cb are formed in a cross shape and orthogonal to each other inside the annular frame portions 10Ea and 10Eb. ing. The four device pattern regions 8b partitioned by the annular frame portions 10Ea and 10Eb and the cross frame portions 10Ca and 10Cb are connected to the branch frame portions 10Ba and 10Bb provided by branching from the cross frame portions 10Ca and 10Cb. A plurality of device pattern portions 10Pa and 10Pb (see FIG. 3) are patterned.

By subjecting the front and back surfaces of the quartz substrate 8 to dry etching, the exposed portion of the quartz crystal is removed without being covered with the device pattern portions 10Pa and 10Pb in the device pattern region 8b. Nine outlines and grooves 9c and 9d are formed. Thereafter, the device pattern portions 10Pa and 10Pb are individually separated from the branch frame portions 10Ba and 10Bb to obtain the individual crystal resonator 9 shown in FIG. The regions of the annular frame portions 10Ea and 10Eb and the cross frame portions 10Ca and 10Cb have a function of maintaining the entire shape of the crystal substrate 8 in the process of manufacturing the crystal resonator 9 from the crystal substrate 8 by dry etching. Further, in the plasma processing for dry etching, it functions as a support portion for supporting the quartz crystal substrate 8 from the lower surface side.

  In the description of the dry etching process in FIG. 5 and subsequent figures, the cross-sectional shape of the quartz crystal substrate 8 is simplified as shown in FIG. That is, in FIG. 4B, the annular frame portions 10Ea and 10Eb shown on the upper and lower surfaces of both sides of the quartz substrate 8 are mask layers formed on the front surface 8c and the back surface 8d of the peripheral portion of the quartz substrate 8. Only a part of the plurality of device pattern portions 10Pa and 10Pb formed in the four device pattern regions 8b is shown in a simplified manner.

  Here, these mask layers 10a and 10b are metal masks made of a metal such as Ni and Cr, and are formed in a desired pattern by photolithography. By using a metal mask as in the present embodiment, the following effects are obtained. That is, under the etching conditions of quartz (quartz substrate 8), the resist mask etching selectivity is about 1 to 3, and when the processing depth is about several tens to several hundreds μm as in this embodiment, the resist mask The thickness needs to be several tens of μm. This thick resist mask of several tens of micrometers has a large dimensional variation in consideration of the performance and cost of the exposure apparatus. On the other hand, the etching selectivity of a metal mask such as Ni or Cr under quartz etching conditions is about 20 to 40. Therefore, when the processing depth is about several tens to several hundreds of μm, the thickness of the metal mask is 3 to 3. It may be about 5 μm, and can be formed with high accuracy while suppressing variation in dimensions.

  However, since the metal mask is heated during the dry etching of the quartz substrate 8 and becomes high temperature, and the thickness of the metal mask is changed by cutting the metal mask, an internal stress is generated. This internal stress causes the warp of the quartz substrate 8 on which the metal mask is formed. That is, when a metal mask made of metal is used, warpage of the quartz crystal substrate 9 due to heat and cracking due to heat are more likely to occur during dry etching than when a resist mask is used. In this embodiment, as will be described in detail later, the quartz substrate 8 on which the metal mask is formed with high efficiency and high accuracy can be cooled and maintained at a relatively low temperature during dry etching. Is reduced or mitigated to prevent warping of the crystal substrate 8 due to heat during dry etching and damage such as cracks caused by the warpage.

  Further, in the present embodiment, the mask layers 10a and 10b are formed on both the front surface 8c and the back surface 8d of the quartz substrate 8, so that the mask layer is formed only on one of the front surface 8c and the back surface 8d. Thus, the internal stress of the mask layers 10a and 10b, which has become a high temperature during dry etching, acts equally on the front surface 8c and the back surface 8d of the quartz substrate 8. In this respect as well, damage such as warpage of the crystal substrate 8 due to heat during dry etching and cracks resulting therefrom is prevented.

  Next, details of (ST1A) and (ST2A) shown in FIG. 2 will be described with reference to FIGS. First, as shown in FIG. 5A, a resin substrate 7a and an adhesive film 7b are prepared. The resin substrate 7 a is shaped in advance according to the outer shape of the quartz substrate 8. The resin substrate 7a contains conductive particles 11a that are unevenly distributed on the lower surface side and have conductivity such as metal particles, and the thickness range in which the conductive particles 11a are contained forms the conductive layer 7c. In addition, as a structure for forming the conductive layer on the resin substrate 7a, instead of containing the conductive particles 11a in the resin substrate 7a, a metal film or the like is formed on the lower surface side of the resin substrate 7a as shown in the wavy brackets in the figure. The conductive film 11b may be attached.

Next, as shown in FIG. 5 (b), the adhesive film 7b is laminated and pasted on the resin substrate 7a, and the adhesive film 7b is cut in accordance with the outer shape of the resin substrate 7a. As shown in FIG. 6, this pasting process is performed in a vacuum atmosphere of a vacuum chamber 2 a provided in the vacuum pasting apparatus 2. Cover films 13a and 13b are attached to both sides of the adhesive film 7b, and a supply roll 14 in which the adhesive film 7b with the cover films 13a and 13b is wound in the chamber 2a of the vacuum applicator 2 is provided. Supplied in the state of One cover film 13a (lower side in the figure) is peeled off by the peeling roll 15a from the pressure-sensitive adhesive film 7b unwound from the supply roll 14, and is guided and collected by the guide roll 15b.

  The adhesive film 7b from which the cover film 13a has been peeled is guided in the horizontal direction by the guide roller 15c in a state where the cover film 13b is adhered to the upper surface side. And the lower surface side of the adhesive film 7b exposed by peeling the cover film 13a is attached to the upper surface of the resin substrate 7a. Next, the adhesive film 7a and the other cover film 13b are cut along the outer contour of the resin substrate 7a by a cutter (not shown), thereby forming an adhesive film on the resin substrate 7a as shown in FIG. The cover tape 13b remains on the support substrate 7 having the configuration in which 7b is attached.

  Thereafter, as shown in FIG. 7B, the other cover tape 13b is peeled off by the peeling tape 17, thereby completing the support substrate 7 having a configuration in which the adhesive film 7b is attached on the resin substrate 7a. In addition, if the adhesive film 7b is heated and softened when it affixes on the resin substrate 7a, the adhesiveness with respect to the resin substrate 7a of the adhesive film 7b can further be raised. As specific conditions for the vacuum application, for example, the degree of vacuum in the vacuum chamber 2a (based on absolute vacuum) is about 50 to 300 Pa, and the stage temperature is about room temperature to about 80 ° C. That is, in the above-described process, a support substrate 7 is prepared, which is made of a material that can be dissolved by wet etching and has a pressure-sensitive adhesive layer 7b formed in advance on one side by a pressure-sensitive adhesive film 7b (substrate preparation process). ). In the following description of the process, the adhesive film 7b attached to the resin substrate 7a is described as the adhesive layer 7b of the support substrate 7. That is, in this embodiment, the support substrate 7 is provided with the conductive layer 7c provided on the surface opposite to the surface on which the adhesive layer 7b is formed.

  In the present embodiment, the pressure-sensitive adhesive film 7b is made of a polyimide-based pressure-sensitive adhesive having a constant thickness, and the resin substrate 7a and the cover films 13a and 13b are made of polyethylene terephthalate (PET). The thickness of the pressure-sensitive adhesive film 7a is about 40 μm, and the thickness of the cover films 13a and 13b is about 70 μm. The functions required for the adhesive film 7a include having sufficient adhesive strength, high heat resistance, almost no outgas even under reduced pressure and high temperature (for example, 5 ppm or less), and being easily removable by wet etching. is there. As long as these functions are satisfied, the type and thickness of the pressure-sensitive adhesive constituting the pressure-sensitive adhesive film 7a are not particularly limited.

  Thereafter, the support substrate 7 thus prepared is bonded to the crystal substrate 8. That is, the support substrate 7 and the crystal substrate 8 are sent to the vacuum bonding apparatus 3 having a configuration in which the fixed portion 3b and the movable portion 3c are provided in the vacuum chamber 3a in which a vacuum atmosphere can be formed. Then, as shown in FIG. 5C, the support substrate 7 is placed on the fixed portion 3b with the resin substrate 7a facing downward, and the crystal substrate 8 is placed on the lower surface side of the movable portion 3c with the front surface 8c side. Set in an upward position. In this state, the inside of the vacuum chamber 3a is depressurized, and then the movable portion 3c is lowered to press the quartz substrate 8 against the support substrate 7, as shown in FIG.

  Thereby, the back surface 8d of the first processed surface (front surface 8c) in the dry etching of the quartz substrate 8 is bonded to the adhesive layer 7b of the support substrate 7 (substrate bonding step). By this bonding, the back surface 8d of the quartz substrate 8 is pushed into the adhesive layer 7b. The quartz crystal substrate 8 is pushed into the pressure-sensitive adhesive layer 7b until the device pattern portion 10Pb formed on at least the back surface 8d is completely buried in the pressure-sensitive adhesive layer 7b. As specific conditions for vacuum bonding, for example, the degree of vacuum in the vacuum chamber 3a is about 100 to 750 Pa on the basis of absolute vacuum, the stage temperature is about room temperature to about 80 ° C., and the quartz substrate 8 is pressed against the support substrate 7. The pressure is about 0.1 to 1 MPa.

  Thereby, as shown in FIG. 8, the support substrate 7 and the crystal substrate 8 are bonded together, and a workpiece 16 to be subjected to dry etching of (ST3A) is prepared. As shown in FIG. 8A, the workpiece 16 has a form in which the back surface 8d of the crystal substrate 8 is in close contact with the adhesive layer 7b and the device pattern portion 10Pb is embedded in the adhesive layer 7b. In the following description of the dry etching process, as shown in FIG. 8B, the device pattern portions 10Pa and 10Pb in the device pattern region 8b are not shown and are simplified.

  Thus, by sticking the support substrate 7 and the crystal substrate 8 in the vacuum chamber 3a of the vacuum bonding apparatus 3, there is no bubble between the adhesive layer 7b and the crystal substrate 8, and the adhesive layer 7b. It is possible to increase the degree of adhesion of the quartz substrate 8 to the substrate. Further, since the quartz substrate 8 is bonded so that at least the device pattern portion 10Pb formed on the back surface 8d is completely embedded in the adhesive layer 7b, the adhesion area between the quartz substrate 8 and the adhesive layer 7b is large. Note that the pressure-sensitive adhesive layer 7b may be heated when the quartz substrate 8 and the pressure-sensitive adhesive layer 7b are pressed and bonded together by the vacuum bonding apparatus 3. Since the pressure-sensitive adhesive layer 7b is softened by heating, the pressure-sensitive adhesive layer 7b can be reliably adhered to the uneven portion of the back surface 8d of the crystal substrate 9 formed by the device pattern portion 10Pb without any gap.

  Next, the detailed structure and function of the dry etching apparatus 4 will be described with reference to FIGS. The dry etching apparatus 4 includes a depressurizable chamber (vacuum container) 20 that constitutes a processing chamber in which plasma processing is performed on the workpiece 16 as an object. The upper end opening of the chamber 20 is closed in a sealed state by a top plate 21 made of a dielectric material such as quartz. An ICP coil 22 is disposed on the top plate 21, and a high frequency power supply 24 is electrically connected to the ICP coil 22 via a matching circuit 23. A substrate susceptor 25 having a function as a lower electrode to which a bias voltage is applied and a function as a holding table for the workpiece 16 is disposed on the bottom side in the chamber 20 facing the top plate 21.

  The chamber 20 is provided with a loading / unloading gate 20a for loading / unloading the workpiece 16. In the present embodiment, the workpiece 16 is carried into the chamber 20 through the gate 20 a while being held in a plurality of substrate storage holes 29 a provided in the tray 29, and in this state with respect to the workpiece 16. Plasma processing is performed. An etching gas supply source 26 is connected to the etching gas supply port 20 b provided in the chamber 20. The etching gas supply source 26 includes an MFC (mass flow controller) and the like, and can supply the etching gas at a desired mixing ratio and flow rate from the etching gas supply port 20b. Further, a vacuum exhaust device 27 including a vacuum pump or the like is connected to the exhaust port 20 c provided in the chamber 20.

  The substrate susceptor 25 is made of a dielectric plate 32 made of ceramics or the like, aluminum or the like having an alumite coating on the surface, a metal plate 35 functioning as a pedestal electrode, a spacer plate 36 made of ceramics or the like, and a guide cylinder made of ceramics or the like. 37, a metal earth shield 38, and a ring-shaped guide member 28 for guiding the tray 29. The dielectric plate 32 constituting the uppermost portion of the substrate susceptor 25 is fixed to the upper surface of the metal plate 35, and the metal plate 35 is fixed on the spacer plate 36. Further, the guide cylinder 37 covers the outer periphery of the dielectric plate 32 and the metal plate 35, and the ground shield 38 covers the outer periphery and the outer periphery of the spacer plate 36, and the guide member 28 is mounted on the upper surface of the earth shield 38. .

The dielectric plate 32 is a substantially disc member having a circular outer shape in plan view, and the substrate 16 described below is a workpiece 16 in which the crystal substrate 8 to be etched is bonded to the support substrate 7 in the substrate susceptor 25. It has a function as a substrate mounting portion that is mounted via the support portion 33. 10A, the upper end surface of the dielectric plate 32 constitutes a tray support surface (tray support portion) 32a that supports the lower surface 29c of the tray 29. A short columnar substrate support portion 33 on which the crystal substrate 8 is placed via the support substrate 7 protrudes upward at a position corresponding to each substrate accommodation hole 29a of the tray 29 on the tray support surface 32a. ing. The substrate support portion 33 is provided with an annular convex portion 33a provided in an annular shape and a cylindrical convex portion 33b provided with a small-diameter cylindrical shape that is uniformly distributed within a range surrounded by the annular convex portion 33a. It has. The upper end surfaces of the annular convex portion 33a and the columnar convex portion 33b constitute a substrate mounting surface 33c on which the quartz crystal substrate 8 is mounted on the dielectric plate 32 which is a substrate mounting portion.

  In the chamber 20, there are provided lifting pins 31 that pass through the substrate susceptor 25 and are driven by a driving device 30 to move up and down. The lifting pins 31 abut on the lower surface of the tray 29 to raise and lower the tray 29. As a result, the tray 29 comes in contact with and separates from the dielectric plate 32, and the workpiece 16 held in the substrate accommodation hole 29 a of the tray 29 is placed on the substrate support portion 33 and separated from the substrate support portion 33.

  The tray 29 has a substantially disc shape, and a conical tapered surface 29d having a constricted shape is formed on the outer peripheral edge. A conical taper surface 28 a having a tapered shape is formed on the inner peripheral edge of the guide member 28. When the tray 29 supported by the elevating pins 31 is lowered, the conical taper surface 29d is fitted into the conical taper surface 28a, so that the tray 29 is positioned at a correct position with respect to the substrate susceptor 25. Is supported in contact with the tray support surface 32a. Examples of the material of the tray 29 include alumina (Al2O3), aluminum nitride (AlN), zirconia (ZrO), yttria (Y2O3), silicon nitride (SiN), ceramic materials such as silicon carbide (SiC), quartz, and glass. Including dielectric materials can be used. Metals such as aluminum coated with alumite, aluminum coated with ceramics on the surface, and aluminum coated with a resin material may be used.

  The tray 29 is provided with a plurality of substrate storage holes 29a penetrating in the thickness direction. As shown in FIG. 10 (a), the lower surface side of the tray 29 extends from the inner peripheral wall 29e of the substrate storage hole 29a. Is provided with a support edge portion 29b extending toward the center of the substrate housing hole 29a. The lower surface of the work 16 placed in the substrate housing hole 29a is held from below by the support edge 29b. The outer diameter R1 of the substrate support 33 is set to be smaller than the inner diameter R2 of the circular opening surface enclosed by the support edge 29b, and the protrusion height H1 of the substrate support 33 is the support edge. It is set larger than the thickness height H2 of 29b.

  Accordingly, as shown in FIG. 10B, in a state where the raising / lowering pins 31 are lowered and the tray 29 is positioned at the guide position by the guide member 28, the substrate support portion 33 of the tray 29 is placed in each substrate storage hole 29 a. It enters the substrate housing hole 29a from the lower surface side. Thereby, the lower surface of the tray 29 is supported by the tray support surface 32a. In this state, the workpiece 16 is separated from the support edge portion 29b in each substrate housing hole 29a, and the lower surface is supported by the upper surfaces of the annular convex portion 33a and the cylindrical convex portion 33b.

  As shown in FIGS. 9 and 10, in the vicinity of the substrate mounting surface 33 c of each substrate support portion 33 of the dielectric plate 32, a substrate adsorption electrode that is a circular plate-like single electrode type electrostatic adsorption electrode. 34 is built in. The substrate adsorption electrodes 34 are electrically insulated from each other, and a DC voltage for electrostatic adsorption is applied from a common DC voltage application mechanism 40 including a DC power supply 41 and an adjustment resistor 42. The substrate adsorption electrode 34 may be a bipolar electrostatic adsorption electrode. Further, one electrostatic chucking electrode may be provided in common for the plurality of substrate support portions 33.

As shown in FIGS. 9 and 10, each substrate support portion 33 is provided with a gas supply hole 52 for heat transfer gas (helium in the present embodiment). These gas supply holes 52 are connected to a common heat transfer gas supply mechanism 43. The heat transfer gas supply mechanism 43 includes a heat transfer gas source (in this embodiment, a helium gas source) 44, a supply channel 45 from the heat transfer gas source 44 to the gas supply hole 52, and a heat transfer gas source of the supply channel 45. A flow meter 46, a flow control valve 47, and a pressure gauge 48 are provided in this order from the 44 side. The heat transfer gas supply mechanism 43 includes a discharge flow channel 51 that branches from the supply flow channel 45, and a cut-off valve 49 provided in the discharge flow channel 51. Furthermore, the heat transfer gas supply mechanism 43 includes a bypass flow path 50 that connects the supply hole 52 side and the discharge flow path 51 with respect to the pressure gauge 48 of the supply flow path 45.

  In each substrate support portion 33, the substrate placement surface 33c on which the workpiece 16 is placed, in other words, in the space 33d enclosed by the lower surface of the workpiece 16 and the annular convex portion 33a is closed in the heat transfer gas. Heat transfer gas is supplied by the supply mechanism 43. When supplying the heat transfer gas, the cutoff valve 49 is closed, and the heat transfer gas is sent from the heat transfer gas source 44 to the supply hole 52 through the supply flow path 45. Based on the flow rate and pressure of the supply flow path 45 detected by the flow meter 46 and the pressure gauge 48, a controller 59 described later controls the flow rate control valve 47. On the other hand, when the heat transfer gas is discharged, the cut-off valve 49 is opened, and the heat transfer gas in the space 33d on the lower surface of the workpiece 16 is exhausted through the gas supply hole 52, the supply flow path 45, and the discharge flow path 51. The

  A high frequency application mechanism 53 that applies a bias voltage, which is a high frequency voltage for generating plasma, is electrically connected to the metal plate 35. The high frequency application mechanism 53 includes a high frequency power supply 54 and a matching variable capacitor 55. Inside the metal plate 35, a refrigerant circulation part 35a is provided (see also FIG. 10A), and the refrigerant circulation part 35a is connected to a refrigerant circulation device 57 via a refrigerant pipe 58. By operating the refrigerant circulation device 57, the refrigerant circulates in the refrigerant circulation portion 35a, and the metal plate 35 heated by the heat generated by the plasma processing is cooled. The refrigerant circulation device 57, the refrigerant pipe 58, and the refrigerant circulation unit 35 a constitute a cooling mechanism 56 that cools the metal plate 35.

  A controller 59 schematically shown only in FIG. 1 is based on various sensors and operation inputs including a flow meter 46 and a pressure gauge 48, and a high-frequency power source 24, an etching gas supply source 26, a transfer arm 60, a vacuum exhaust device 27, The overall operation of the dry etching apparatus 4 including the drive device 30, the DC voltage application mechanism 40, the heat transfer gas supply mechanism 43, the high-frequency voltage application mechanism 53, and the cooling mechanism 56 is controlled.

  With reference to FIG. 11 and FIG. 12, the operation of loading the workpiece 16 and placing the workpiece 16 on the substrate susceptor 25 in the dry etching apparatus 4 will be described. First, as shown in FIG. 12A, a work 16 (see FIG. 8) configured by bonding the quartz substrate 8 and the support substrate 7 is projected from the hole wall 29e of each substrate receiving hole 29a of the tray 29. The outer peripheral edge portion of the quartz crystal substrate 8 accommodated in the substrate accommodation hole 29a is respectively placed in the plurality of substrate accommodation holes 29a of the tray 29 provided with the support edge portions 29b for supporting the crystal substrate 8 from below through the support substrate 7. .

  Next, the tray 29 holding the plurality of workpieces 16 is held by the transfer arm 60 and is carried into the chamber 20 through the gate 20a (FIG. 9) of the chamber 20, and FIG. 11 (a) and FIG. ), The tray 29 is positioned above the substrate susceptor 25. That is, here, the quartz substrate 8 in which the resin substrate 7 is bonded to the back surface 8d of the front surface 8c, which is a processed surface, is carried into the chamber 20 (vacuum container) of the dry etching apparatus 4 in the form of a work 16, and the quartz substrate A plurality of workpieces 16 are placed on the substrate placement surface 33c of each substrate support portion 33 of the dielectric plate 32 (substrate placement portion) in a posture in which the surface 8c which is the processing surface 8 is directed upward (substrate loading) Process).

At this time, as shown in FIG. 11A, the tray 29 is transferred from the transport arm 60 to the lift pins 31 by raising the lift pins 31 to support the lower surface of the tray 29. Next, after the transfer arm 60 is retracted outside the chamber 20, as shown in FIG. 11 (b), the tray 29 is lowered with respect to the substrate susceptor 25 together with the held work 16 by starting the descent of the elevating pins 31. .

  When the lower surface of the tray 29 comes into contact with the tray support surface 32a of the dielectric plate 32, the workpiece 16 is spaced upward from the support edge portion 29b of the tray 29 in each substrate storage hole 29a and the substrate support portion 33. In this state, dry etching is performed by plasma processing on the quartz substrate 8. In the concave portion surrounded by the annular convex portion 33a of each substrate support portion 33, a columnar convex portion 33b that contacts the lower surface of the support substrate 7 and a gas supply hole 52 are provided. When the tray 29 is unloaded after the plasma processing is finished, the lifting pins 31 are raised to raise the tray 29 holding the workpiece 16 to the transfer position to the transfer arm 60, and the transfer arm 60 that has advanced into the chamber 20 is moved to the transfer arm 60. The tray 29 is transferred.

  Next, with reference to FIG. 13, a description will be given of plasma processing for the quartz substrate 8 that is executed to manufacture the quartz resonator 9. Here, the etching process is performed by the dry etching apparatus 4 on the surface 8c set as the first processing surface among the two surfaces of the surface 8c and the back surface 8d of the quartz substrate 8. In FIG. 13, only one workpiece 16 among the plurality of workpieces 16 held on the tray 29 is illustrated in a simplified manner.

  As shown in FIG. 13A, the workpiece 16 is placed on the substrate placement surface 33 c of the substrate support portion 33 in the substrate accommodation hole 29 a. At this time, a DC voltage is applied from the DC voltage application mechanism 40 to the substrate adsorption electrode 34 incorporated in the substrate support 33, and the lower surface of the support substrate 7 (the conductive layer 7c is formed as described above). Is electrostatically attracted to the substrate placement surface 33c, whereby the support substrate 7 is held on the substrate placement surface 33c with high adhesion. That is, here, a DC voltage is applied to the substrate adsorption electrode 34 to hold the support substrate 7 by electrostatic adsorption on the substrate mounting surface 33c (substrate adsorption holding step).

  Next, a heat transfer gas (He in this embodiment) is supplied from the heat transfer gas supply mechanism 43 through the gas supply hole 52, and a space 33 d (spaced) formed between the lower surface of the support substrate 7 in the substrate support 33. The heat transfer gas is filled in the recesses. Thereafter, the etching gas is supplied from the etching gas supply source 26 into the chamber 20 through the etching gas supply port 20b, and the vacuum exhaust device 27 is evacuated to maintain the inside of the chamber 20 at a predetermined pressure.

  Next, a high frequency voltage is applied from the high frequency power source 24 to the ICP coil 22, and a bias voltage is applied to the metal plate 35 of the substrate susceptor 25 by the high frequency application mechanism 53 to ionize the etching gas and generate plasma P in the chamber 20. Let In the above configuration, the high frequency power supply 24, the ICP coil 22, and the high frequency application mechanism 53 constitute a plasma generation source that generates plasma P by ionizing an etching gas in the chamber 20 that is a vacuum vessel. Then, the surface 8c of the quartz crystal substrate 8 is etched by the plasma P. Specifically, a portion of the surface 8c of each crystal substrate 8 that is not covered with the device pattern portion 10Pa, that is, an outer portion of the device pattern portion 10Pa that indicates the outer contour of the crystal resonator 9 and a portion of the groove 9c Etched. That is, here, the heat transfer gas is supplied between the substrate mounting surface 33c and the resin substrate 7a by the heat transfer gas supply mechanism 43, while the plasma P is generated by the plasma generation source to etch the processed surface of the quartz substrate 8. (Etching process).

In order to increase the etching rate of the quartz substrate 8, it is necessary to apply a high bias voltage to the metal plate 35 with a high plasma density. Further, since the quartz substrate 8 has a high hardness, the etching time becomes long even if the plasma density is increased and a high bias voltage is applied. Therefore, the quartz substrate 8 is exposed to heat from the plasma for a long time, and the heat absorption from the plasma is remarkable. The quartz substrate 8 is about 100 μm and is very thin and brittle. Therefore, assuming that the quartz substrate 8 is not sufficiently cooled, damage such as warpage due to heat and cracks resulting from the warpage occurs.

  Further, the higher the temperature of the quartz substrate 8, the greater the internal stress due to the difference in the coefficient of thermal expansion between the quartz substrate 8 and the device pattern portion 10Pa, causing damage such as warping and cracking. Further, when the quartz substrate 8 is moved to a high temperature of about 400 ° C. to 500 ° C., the quartz itself is altered. However, in this embodiment, since the quartz substrate 8 can be cooled and maintained at a relatively low temperature with high efficiency and high accuracy, the etching conditions (high plasma density, high bias voltage, In addition, the quartz substrate 8 can be prevented from being damaged due to heat while satisfying a long processing time. Hereinafter, this point will be described in detail.

  During the etching, the refrigerant is circulated in the refrigerant circulation part 35 a by the refrigerant circulation device 57 to cool the metal plate 35, thereby cooling the crystal substrate 8 bonded to the support substrate 7. That is, the quartz substrate 8 is cooled by heat conduction between the pressure-sensitive adhesive layer 7 b, the resin substrate 7 a, the heat transfer gas, and the metal plate 35 via the dielectric plate 32. In the present embodiment, since the adhesive layer 7b is attached to the resin substrate 7a by vacuum bonding, the degree of adhesion of the adhesive layer 7b to the resin substrate 7a is high, and the adhesive layer 7b and the resin substrate 7a have a high degree of adhesion. There are no air bubbles inside. Further, since the crystal substrate 8 is bonded to the resin substrate 7a via the adhesive layer 7b by vacuum bonding, the degree of adhesion of the crystal substrate 8 to the adhesive layer 7b is high, and the crystal substrate 8 and the adhesive layer 7b There are no air bubbles between them. In addition, the quartz substrate 8 is pushed into the pressure-sensitive adhesive layer 7b to a sufficient depth, and the contact area between the two is large. Therefore, the thermal conductivity between the adhesive layer 7b and the resin substrate 7a and the thermal conductivity between the adhesive layer 7b and the quartz substrate 8 are both good.

  Further, as described above, the lower surface of the work 16 is directly placed on the substrate placement surface 33c without the tray 29, and is held with high adhesion to the substrate placement surface 33c by electrostatic adsorption. Therefore, the space 33d filled with the heat transfer gas surrounded by the annular convex portion 33a and the lower surface of the work 16 has a high degree of sealing, and the space between the work 16 and the substrate placement surface 33c via the heat transfer gas is high. Good thermal conductivity. As a result, the quartz crystal substrate 8 of the workpiece 16 held on the substrate placement surface 33c of each substrate support portion 33 can be cooled with high cooling efficiency. By thus cooling the quartz substrate 8 with high efficiency, the quartz substrate 8 is maintained at about 100 ° C. or less even under etching conditions of high plasma density, high bias voltage, and long processing time (for example, about 80 minutes). it can. As a result, it is possible to prevent the quartz substrate 8 from being warped, peeled off, cracked, or altered during the dry etching.

  Further, it is possible to prevent damage such as warpage, peeling, and cracking of the quartz substrate 8 due to peeling of the adhesive layer 7b from the quartz substrate 8 and the resin substrate 7a and expansion of bubbles due to heat during dry etching. Furthermore, by cooling the quartz substrate 8 with high efficiency and high accuracy, the internal stress due to the difference in thermal expansion coefficient between the quartz constituting the quartz substrate 8 and the metal constituting the device pattern portion 10Pa can be reduced. It is also possible to prevent damage caused by. Furthermore, since the quartz substrate 8 does not become high temperature due to high-efficiency and high-precision cooling, it is possible to prevent the quartz itself from being altered by heat.

  As described above, the quartz substrate 8 is pushed into the pressure-sensitive adhesive layer 7b to such a depth that at least the device pattern portion 10Pb formed on the back surface 8d is completely buried in the pressure-sensitive adhesive layer 7b. In this way, by burying the back surface 8d of the quartz substrate 8 to a sufficient depth in the adhesive layer 7b, it is possible to prevent plasma from entering the boundary between the back surface 8d of the quartz substrate 8 and the adhesive layer 7b. When the plasma P wraps around the boundary between the back surface 8d of the quartz substrate 8 and the adhesive layer 7b, the adhesive layer 7b at the boundary portion is etched, causing peeling of the quartz substrate 8 from the adhesive layer 7b. Further, the quartz substrate 8 is buried in the adhesive layer 7b to a sufficient depth to prevent the plasma from wrapping around, so that the quartz substrate 8 can be prevented from being peeled off from the adhesive layer 7b, and the quartz substrate 8 can be removed from the resin substrate 7a. Thus, it is possible to maintain a close contact state via the pressure-sensitive adhesive layer 7b.

Specific etching conditions in this embodiment are as follows. The etching gas is a C ₄ F ₈ / He mixed gas, and the flow rate of each gas is 30 sccm for C ₄ F _{8 and} 120 sccm for He. The pressure in the chamber 20 is 0.5 Pa. The high frequency power applied to the ICP coil 22 is 1500 W, and the bias power applied to the metal plate 35 is 700 W. The voltage applied to the substrate adsorption electrode 34 is +1.2 kV. The filling pressure of the heat transfer gas (He in this embodiment) into the gap between the support substrate 11 and the substrate mounting surface 41a is 1200 Pa. The temperature of the substrate susceptor 25 is maintained at about 20 ° C., whereby the temperature of the quartz substrate 8 is maintained at about 100 ° C. or less.

The etching rate of the quartz substrate 8 under these etching conditions is 0.5 to 1.0 μm / min. The etching selectivity of the mask layers 13a and 13b made of a metal such as Ni or Cr is about 20 to 40. The etching time is about 40 to 80 minutes. The etching gas is not limited to the C ₄ F ₈ / He mixed gas. Instead of C ₄ F ₈ , other fluorocarbon gases can be used. For _example, can be used _{CHF 3, CF 4, C 4} F 6, C 5 F 8, CH 2 F 2 or the like. Other than the fluorocarbon-based gas, SF ₆ , NF ₃ or the like can be used. In addition, other noble gases such as Ar and Xe may be used instead of He.

  Thereafter, as shown in FIG. 13 (b), the outer surface 8c of the device pattern portion 10Pa showing the outer contour of the crystal unit 9 is etched to a depth of ½ of the outer cross section of the crystal unit 9. When the etching depth 9c reaches the bottom, the etching of the surface 8c of the quartz substrate 8 is finished. When this etching is completed, in the region outside the device pattern portion 10Pa indicating the outer contour of the crystal unit 9, the crystal frame 8 is removed except for the annular frame portion 10Ea, the branch frame portion 10Ba, and the cross frame portion 10Ca. Quartz is removed with approximately half the thickness in the thickness direction. The depth at which the crystal substrate 8 is pushed into the pressure-sensitive adhesive layer 7b is the same as the depth from the resin substrate 7a to the surface of the pressure-sensitive adhesive layer 7b at the end of etching of the surface 8c of the crystal substrate 8. 8 is preferably set according to the selection ratio of the resin substrate 7a and the pressure-sensitive adhesive layer 7b so as to be higher than the height up to the back surface 8d. Thereby, it is possible to more reliably prevent plasma from entering the boundary between the back surface 8d of the quartz substrate 8 and the adhesive layer 7b until the etching of the front surface 8c of the quartz substrate 8 is completed.

  After the etching of the surface 8 c of the quartz substrate 8 is completed, the application of the high frequency voltage from the high frequency power supply 24 to the ICP coil 22 and the application of the bias voltage from the high frequency application mechanism 53 to the metal plate 35 are stopped. Subsequently, the etching gas is exhausted from the chamber 20 by the vacuum exhaust device 27. Further, the application of the DC voltage from the DC voltage application mechanism 40 to the substrate adsorption electrode 34 is stopped, and the electrostatic adsorption of the workpiece 16 is released. Thereafter, the workpiece 16 having the quartz substrate 8 bonded to the support substrate 7 is carried out of the chamber 20 of the dry etching apparatus 4 from the gate 20a.

  At this time, the workpiece 16 is first lifted from the substrate placement surface 33c by driving the elevating pins 31 by the driving device 30, and then the workpiece 16 is transferred to the transfer arm 60 (FIG. 11), and then the workpiece is moved together with the transfer arm 60. 16 is carried out of the chamber 20. At this time, since the quartz substrate 8 is in a state of being bonded to the support substrate 7, damage to the quartz substrate 8 due to an external force acting during the carry-out operation can be prevented. That is, here, after completion of the etching process, the quartz crystal substrate 8 is lifted from the substrate mounting surface 33c together with the support substrate 7, and is unloaded from the chamber 20 (substrate unloading process). As a result, as shown in FIG. 14A, the workpiece 16 is in a state in which the quartz substrate 8 * on which the dry etching of the surface 8c has been completed is supported by the support substrate 7.

In the present embodiment, by providing the conductive layer 7c on the lower surface of the resin substrate 7a as described above, the electrostatic adsorption force that attracts the support substrate 7 to the upper surface of the substrate support portion 33 by the substrate adsorption electrode 34 is strengthened, The support substrate 7 is effectively cooled by heat conduction with the dielectric plate 32, and conveyance trouble is prevented. That is, by providing the conductive layer 7c, the residual adsorption is prevented while increasing the adsorption force at the time of electrostatic adsorption. If the conductive layer 7c is not provided, the suction force of the substrate mounting surface 33c for electrostatically holding and supporting the support substrate 7 is weakened, so that the cooling effect of the support substrate 7 due to heat conduction with the dielectric plate 32 is weakened. In order to increase the cooling capacity of the support substrate 7 by heat conduction with the dielectric plate 32 without providing the conductive layer 7c, it is necessary to apply a very high voltage to the substrate adsorption electrode 34.

  In this case, as conceptually shown in FIG. 19 (b), the substrate mounting surface after the resin substrate 7a, which is a dielectric, is electrostatically polarized and the application of the voltage to the substrate attracting electrode 34 is stopped. Electrostatic polarization remains on the lower surface of the resin substrate 7a in contact with 33c, and strong residual adsorption occurs between the lower surface of the resin substrate 7a and the substrate mounting surface 33c due to residual charges. Due to this strong residual adsorption, there is a possibility that a trouble in conveyance such as the support substrate 7 is difficult to peel off or not peeled off from the substrate mounting surface 33c. On the other hand, as conceptually shown in FIG. 19A, when the conductive layer 7c is provided, if the application of the DC voltage from the DC voltage application mechanism 40 is stopped, The adsorption force of the substrate mounting surface 33c disappears quickly due to the movement of the charges. Thereby, the conveyance trouble at the time of separating the support substrate 7 from the substrate mounting surface 33c can be prevented.

  Next, a process of dissolving and removing the support substrate 7 from the above-described quartz substrate 8 * is executed (ST4A in FIG. 2). That is, as shown in FIG. 14B, the workpiece 16 is carried into the treatment tank 5a of the wet etching apparatus 5 and immersed in a chemical solution for wet etching. In the present embodiment, as described above, since the resin substrate 7a is made of PET and the adhesive layer 7b is made of a polyimide-based adhesive, an organic solvent such as acetone or NMP (N-methyl-pyrrolidone) is used as a chemical solution. However, the type of the chemical solution is appropriately selected according to the material of the resin substrate 7a and the adhesive layer 7b. Thereby, the resin substrate 7a and the adhesive layer 7b constituting the support substrate 7 are dissolved and disappeared by the chemical action of the chemical solution, and only the quartz substrate 8 * remains.

  Thereafter, the quartz substrate 8 * is turned upside down, so that the quartz substrate 8 * is in a posture in which the back surface 8d, which is a processed surface in the next process, faces upward as shown in FIG. 14C. That is, here, only the quartz substrate 8 * is separated and taken out by dissolving the support substrate 7 together with the adhesive layer 7b by wet etching (substrate separation step). In this substrate separation step, the support substrate 7 is easily dissolved by appropriately selecting the combination of the material of the resin substrate 7a and the pressure-sensitive adhesive layer 7b constituting the support substrate 7 and the type of the chemical solution, and the crystal substrate 8 *. Can be efficiently separated (for example, an etching time of about 1 to 2 hours). Thereafter, the quartz substrate 8 * is cleaned by the cleaning device 6 to remove the chemical component, and then sent to the next etching process for the back surface 8d.

  FIG. 15 shows an example in which the conductive film 11 b is attached to the resin substrate 7 a as a method for forming the conductive layer 7 c on the resin substrate 7 a constituting the support substrate 7. Here, FIGS. 15A and 15C are the same as FIGS. 14A and 14C, and only FIG. 15B is different from the example shown in FIG. That is, in the example shown in FIG. 14, the conductor particles 11a contained in the resin substrate 7a are dispersed in the chemical solution during the wet etching process. On the other hand, in the example shown in FIG. 15, since the conductive film 11b remains in the chemical solution while maintaining its shape, the process of collecting and discarding the conductive film 11b from the processing tank 5a in the course of wet etching is performed. Necessary.

Next, etching of the back surface 8d of the quartz substrate 8 will be described with reference to FIGS. This back surface 8d etching process ((ST1B) to (ST4B) in FIG. 2) is a repetition of the same process as the etching process ((ST1A) to (ST4A) in FIG. 2) of the front surface 8c. Hereinafter, the etching process for the back surface 8d will be described, but the points not particularly mentioned are the same as those in the etching of the front surface 8c, including the effects such as the cooling effect in the plasma processing process.

  16 (a) and 16 (b) have the same contents as FIGS. 5 (a) and 5 (b). Here, the adhesive substrate 7a is pasted on the resin substrate 7a, whereby the support substrate 7 having the above-described configuration is used. Is prepared (substrate preparation step). Next, the support substrate 7 thus prepared is bonded to the crystal substrate 8 *. That is, the support substrate 7 and the quartz substrate 8 * are sent to the vacuum bonding apparatus 3 having the above-described configuration. Then, as shown in FIG. 16C, the support substrate 7 is placed on the fixed portion 3b with the resin substrate 7a facing downward, the crystal substrate 8 is placed on the lower surface side of the movable portion 3c, and the back surface 8d side is faced upward. Set in the correct posture. In this state, the inside of the vacuum chamber 3a is depressurized, and then, as shown in FIG. 16 (d), the movable portion 3c is lowered to press the quartz substrate 8 * against the support substrate 7.

  Thereby, the surface 8c which is the back surface of the next processed surface (back surface 8d) in the dry etching of the quartz substrate 8 is bonded to the adhesive layer 7b of the support substrate 7 (substrate bonding step). In this bonding, the processing step generated on the surface 8c by the dry etching in the previous step is pushed into the pressure-sensitive adhesive layer 7b to the depth where it is completely embedded in the pressure-sensitive adhesive layer 7b. As a result, as shown in FIG. 16 (e), a workpiece 16 * is prepared which is configured by bonding the support substrate 7 and the quartz crystal substrate 8 * (ST3B) and is the target of dry etching.

  Next, dry etching is performed on the back surface 8 d of the quartz substrate 8. First, the workpiece 16 * is placed in the substrate accommodation hole 29a of the tray 29, and is carried into the chamber 20 of the dry etching apparatus 4 as in the example shown in FIG. Then, the workpiece 16 * is placed on the substrate placement surface 33c with the back surface 8d, which is the processed surface of the quartz substrate 8 *, facing upward (substrate loading step). That is, as shown in FIG. 17A, the workpiece 16 * is placed on the substrate placement surface 33c of the substrate support 33 in the substrate accommodation hole 29a, and then a DC voltage is applied to the electrostatic chucking electrode 34. Then, the resin substrate 7 is electrostatically adsorbed and held on the substrate mounting surface 33c (substrate adsorption holding step).

  Thereafter, similarly to (ST3A), plasma P is generated in the chamber 20, and plasma processing is performed on the back surface 8d, which is a processed surface. While supplying heat transfer gas between the substrate mounting surface 33c and the resin substrate 7 by the heat transfer gas supply mechanism 43, plasma is generated by the plasma generation source to etch the processed surface of the crystal substrate 8 (etching step). . In this etching, as shown in FIG. 17B, the half depth remaining without being removed by the etching for the surface 8c is etched, and the etching depth of the groove 8e is reduced to the bottom. Etching for the back surface 8d is continued until it reaches. When this etching is completed, the crystal for the entire thickness of the quartz substrate 8 is removed except for the portion of the device pattern portion 10Pb showing the outer contour of the quartz crystal resonator 9 in the device pattern region 8b, and the annular frame portion 10Eb, An opening is formed through the quartz substrate 8 in the thickness direction, leaving the branch frame portion 10Bb and the cross frame portion 10Cb. Further, grooves 9c and 9d (see FIG. 3) are processed on both surfaces of the arm portion 9b in the individual crystal resonator 9.

After the etching for the back surface 8d of the quartz substrate 8 * is completed in this way, the work 16 * in which the quartz substrate 8 * is bonded to the support substrate 7 is moved out of the chamber 20 of the dry etching apparatus 4 from the gate 20a. Unloading (substrate unloading process). Next, a process of dissolving and removing the support substrate 7 from the above-described quartz substrate 8 * is executed (ST4B in FIG. 2). That is, as shown in FIG. 18B, the workpiece 16 is carried into the treatment tank 5a of the wet etching apparatus 5 and immersed in a chemical solution for wet etching. Thereby, the resin substrate 7a and the adhesive layer 7b constituting the support substrate 7 are dissolved and disappeared by the chemical action of the chemical solution, and only the quartz substrate 8 * remains.

  That is, here, by dissolving the support substrate 7 together with the pressure-sensitive adhesive layer 7b by wet etching, the portion excluding the device pattern portion 10Pb is removed by dry etching, and an aggregate of individual pieces of the crystal unit 9 is obtained. Only the quartz substrate 8 * is separated and taken out (substrate separation step). Thereafter, the quartz substrate 8 * is cleaned by the cleaning device 6 to remove the chemical component. Then, by separating the individual crystal resonator 9 from the branch frame portion 10Ba shown in FIG. 4, the outer shape of the crystal resonator 9 is formed and sent to a subsequent process for completing the crystal resonator 9.

  Next, a method for handling the quartz substrate 8 in the present invention and a method for supporting the quartz substrate 8 in the dry etching apparatus 4 will be described. First, in the above-described embodiment, the quartz crystal substrate 8 to be etched is held and carried into and out of the dry etching apparatus 4, and the quartz crystal substrate 8 is mounted on the substrate susceptor 25 provided in the dry etching apparatus 4. As a method of placing and supporting, the following method is adopted.

  First, in the substrate carrying-in process, the substrate of the tray 29 provided with the substrate accommodation holes 29a penetrating in the thickness direction through the quartz substrate 8 having the support substrate 7 bonded to the back surface of the processed surface (the front surface 8c or the back surface 8d). The tray 29 is held in the accommodation hole 29 a and is carried into the chamber 20 of the dry etching apparatus 4 so that the tray 29 is supported by the tray support surface 32 a that is a tray support portion for supporting the tray 29, and the processing surface of the crystal substrate 8 is The crystal substrate 8 is placed on the substrate placement surface 33c from the tray 29 in an upward orientation. At this time, the quartz substrate 8 is moved up and down with respect to the substrate mounting surface 33c via the tray 29 by a plurality of lifting pins 31 provided on the dielectric plate 32 as the substrate mounting portion so as to be movable up and down. In the substrate bonding step, each crystal substrate 8 is bonded to one support substrate 7 to form a workpiece 16, and the substrate of the tray 29 provided with a plurality of substrate accommodation holes 29a in the substrate carry-in step and the substrate carry-out step. A single workpiece 16 is accommodated and held in each of the accommodation holes 29a (see FIG. 12).

  However, the present invention is not limited to the above method, and various crystal substrate 8 handling methods and methods for supporting the crystal substrate 8 in the dry etching apparatus 4 are employed as shown in FIGS. 20 to 22 below. Can do. First, in the example shown in FIG. 20, the workpiece 16 having the support substrate 7A bonded to the back surface of the processed surface of the quartz substrate 8 is inserted into the plurality of substrate accommodation holes 29a provided in the tray 29A, as in the example shown in FIG. Accommodate. Next, as shown in FIG. 20B, the tray 29A is held by the transfer arm 60, and the tray 29A is placed on the dielectric plate 32 (substrate placement portion) of the substrate susceptor 25. The dielectric plate 32 is provided with a substrate support portion 33A that contacts and supports the lower surface of the work 16 at a position corresponding to the arrangement of the work 16 on the tray 29A.

  Here, the support substrate 7A is set to be thinner than the support substrate 7 shown in FIG. 12 in order to shorten the time required for wet etching in the substrate separation step. For this reason, the rigidity of the workpiece 16 is smaller than that of the example shown in FIG. 12 in the state of being bonded to the quartz substrate 8, and there is a possibility that excessive bending occurs and damages in the state of being accommodated in the substrate accommodation hole 29a. In order to prevent such inconvenience due to lack of rigidity, in the example shown in FIG. 20, a support portion set in advance in the quartz substrate 8, that is, a cross frame in the quartz substrate 8 as shown in FIG. Corresponding to the arrangement of the portion 10Ca, a frame-like support member 29f is disposed in each substrate storage hole 29a of the tray 29A, and protrudes from the hole wall 29e of each substrate storage hole 29a of the tray 29A to accommodate the substrate. A support edge portion 29b for supporting the outer peripheral edge portion of the quartz crystal substrate 8 accommodated in the hole 29a from below through the support substrate 7A is provided.

  In the state where the workpiece 16 is accommodated in the substrate accommodation hole 29a of the tray 29A, the quartz substrate 8 is supported by the support edge portion 29b and the support member 29f via the support substrate 7A. Further, in a state where the tray 29A is lowered with respect to the dielectric plate 32, the substantial annular convex portion 33f and the columnar convex portion 33b abut against and support the lower surface of the support substrate 7A, and a plurality of substantial annular shapes. A cross groove 33e formed between the convex portions 33f and formed in a cross shape capable of accommodating the frame-shaped support members 29f of the individual substrate storage holes 29a of the tray 29A accommodates the support members 29f of the tray 29A.

  That is, when the quartz substrate 8 held by the tray 29A and the support substrate 7A are bonded together and the workpiece 16 is lowered with respect to the substrate susceptor 25, the lower surface of the tray 29A comes into contact with the tray support surface 32a of the dielectric plate 32. As a result, the workpiece 16 is transferred to and placed on the substrate placement surface 33c of the substrate support portion 33 while being spaced apart from the support edge portion 29b and the support member 29c of the tray 29A in each substrate storage hole 29a. A state (see FIG. 10B) is obtained. In the concave portion surrounded by each substantial annular convex portion 33f of the substrate support portion 33, a columnar convex portion 33b that contacts the lower surface of the support substrate 7A and a gas supply hole 52 are provided.

  In the example shown in FIG. 21, unlike the examples shown in FIGS. 12 and 20, as shown in FIG. 21A, a plurality of crystal substrates 8 are arranged in advance on a large-diameter support substrate 70. Attaching to 70a. As shown in FIG. 21B, the support substrate 70 to which the plurality of crystal substrates 8 are bonded has a lattice frame-shaped lattice support frame portion 129b connected to the annular portion 129a inside the annular portion 129a. Is held by the tray 129 having the above-described configuration. Here, the arrangement of the crystal substrates 8 on the support substrate 70 is such that the support portions 70 (positions corresponding to the cross frame portion 10Ca) of the respective crystal substrates 8 are lattice support frame portions in a state where the support substrate 70 is held on the tray 129. It is set so as to correspond to the position above 129b. That is, the center point of the cross frame portion 10Ca and the center point of the lattice support frame portion 129b are positioned substantially corresponding to each other, and the cross frame portion 10Ca is positioned such that the lattice support frame portion 129b is supported via the support substrate 70. Is set.

  The support substrate 70 held by the tray 129 is held by the transfer arm 60 together with the tray 129 in FIGS. 21C and 21D, and the dielectric plate 32 (substrate mounting portion) of the substrate susceptor 25. Placed on. On the dielectric plate 32, the crystal substrate 8 is interposed via the support substrate 70 at a position corresponding to at least the arrangement of the crystal substrates 8 in the tray 129 or a position corresponding to the entire support substrate 70 to which the plurality of crystal substrates 8 are bonded. A substrate support portion 33B is provided to contact and support the lower surface of the substrate. The substrate support portion 33B (see FIG. 21D (a partially enlarged view of the substrate support portion 33B in FIG. 21C)) is composed of a plurality of substantial annular projections 33f, and each substantial annular projection In the concave portion surrounded by the portion 33f, a columnar convex portion 33b that contacts the lower surface of the support substrate 70 and a gas supply hole 52 are provided.

  A lattice frame-shaped lattice support frame portion 129b formed between a plurality of substantially annular convex portions 33f constituting the substrate support portion 33B and connected to the annular portion 129a inside the annular portion 129a of the tray 129. The cross groove portion 132 having a cross-sectional shape that fits (accommodates) is disposed, and is positioned at the four end portions of the cross groove portion 132 or on the cross groove portion 132 and is moved up and down with respect to the dielectric plate 32. Pins 31 are provided. The cross groove portion 132 corresponds to the arrangement of the lattice support frame portions 129b in the tray 129. When the tray 129 supported on the lower surface by the elevating pins 31 descends, the cylindrical convex portion 33b contacts the lower surface of the support substrate 70. The support substrate 70 on which the plurality of crystal substrates 8 are bonded together is supported by the lattice support frame portion of the tray 129 by the lattice support frame portion 129b fitting (accommodating) in the cross groove portion 132 (tray support portion). It is spaced apart upward from 129b and delivered to the substrate support portion 33B. As a result, the crystal substrate 8 is placed on the substrate support portion 33 </ b> B via the support substrate 70.

That is, in the example shown in FIG. 21, a plurality of quartz substrates 8 are 1 in the substrate bonding step.
In the substrate carrying-in process and the substrate carrying-out process, the supporting substrate 70 is attached by the frame-shaped tray 129 in which the lattice supporting frame portion 129b is arranged corresponding to the supporting portion set in advance in the crystal substrate 8. The quartz substrate 8 is placed on the substrate support portion 33B of the dielectric plate 32 (substrate placement portion) of the substrate susceptor 25 via the support substrate 70, and a plurality of substantial parts constituting the substrate support portion 33B Each space (in the recess) surrounded by the annular projection 33f and formed between the lower surface of the support substrate 70 is supplied and filled with heat transfer gas (He in this embodiment). As a result, the entire support substrate 70 to which the plurality of crystal substrates 8 are bonded can be supported so as to be cooled, and the plurality of crystal substrates 8 can be effectively cooled via the support substrate 70.

  In the example shown in FIG. 22, as shown in FIG. 22 (a), a plurality of quartz crystal substrates 8 are bonded to a predetermined arrangement position 70a on a large-diameter support substrate 70A. Here, the support substrate 70A is thicker and more rigid than the support substrate 70 shown in FIG. 21, and the support substrate 70A can be directly held by the transfer arm 60 as shown in FIG. 22B. Yes. On the dielectric plate 32 of the substrate susceptor 25, a substrate support portion 33C that supports and supports the lower surface of the crystal substrate 8 via the support substrate 70A at a position corresponding to the arrangement of the crystal substrates 8 in the support substrate 70A and FIG. A cross groove 132 similar to the above is provided.

  The substrate support portion 33C has substantially the same configuration as the substrate support portion 33B shown in FIG. 21, but in the substrate support portion 33C, the upper end portion of the elevating pin 31 is connected to the annular portion 131a inside the annular portion 131a. The lifting / lowering member 131 having a configuration in which the lattice frame-shaped lattice support frame 131b is arranged is coupled, and the lifting / lowering member 131 is lifted / lowered with respect to the dielectric plate 32 by raising / lowering the lifting / lowering pins 31. The support substrate 70 </ b> A is transferred to the elevating member 131 by the transfer arm 60.

  Here, the arrangement of the crystal substrates 8 on the support substrate 70A is such that the support portions (positions corresponding to the cross frame portion 10Ca) of the crystal substrates 8 are lattice support frames in a state where the support substrate 70A is held by the elevating member 131. It is set to be positioned above the part 131b. That is, the center point of the cross frame portion 10Ca and the center point of the lattice support frame portion 131b are positioned substantially corresponding to each other, and the cross frame portion 10Ca is supported by the lattice support frame portion 131b via the support substrate 70A. Is set. By using the elevating member 131 having such a configuration, as shown in FIG. 22 (c), the support portion of each crystal substrate 8 (the position corresponding to the cross frame portion 10Ca) is supported by the lattice support frame portion 131b. It can be supported via 70A. Then, as the elevating member 131 descends, the cylindrical convex portion 33b (FIG. 22B) abuts and supports the lower surface of the support substrate 70A, and the lattice support frame portion 131b fits into the cross groove portion 132, As a result, the quartz crystal substrate 8 is placed on the substrate support portion 33C via the support substrate 70A.

  That is, in the example shown in FIG. 22, a plurality of crystal substrates 8 are bonded to one support substrate 70 </ b> A in the substrate bonding process, and support sites preset in the crystal substrate 8 are handled in the substrate carry-in process and the substrate carry-out process. The support substrate 70A is moved up and down with respect to the substrate support portion 33C (substrate mounting surface) provided on the dielectric plate 32 by the frame-like lifting member 131 on which the lattice support frame portion 131b is arranged.

(Embodiment 2)
In the first embodiment, the support substrate 7 to be bonded to the crystal substrate 8 is configured by attaching the adhesive film 7b to the resin substrate 7a. However, in the second embodiment, the adhesive is previously applied to the PET sheet. A support substrate 107 having a structure in which layers are formed is used. Hereinafter, the configuration of the crystal device manufacturing system 101 and the outline of the manufacturing process of the crystal resonator 9 according to the second embodiment will be described with reference to FIGS.

  The crystal device manufacturing system 101 includes a vacuum bonding apparatus 3, a dry etching apparatus 4, a wet etching apparatus 5, and a cleaning apparatus 6 similar to those shown in the first embodiment. The crystal device manufacturing system 101 has a function of manufacturing a plurality of crystal resonators 9 from the crystal substrate 8 by sequentially dry-etching the crystal substrate 8 (substrate) on which the support substrate 107 is bonded and supported from both the front and back surfaces. Have. In FIG. 23, a solid line and a broken line indicating processing paths correspond to processing processes (process A and process B shown in FIG. 2) for the front and back surfaces of the quartz substrate 8, respectively.

  In the process A, the back surface side of the quartz substrate 8 is first vacuum-bonded and supported by the vacuum bonding apparatus 3 to the support substrate 107, that is, the adhesive layer 107b of the resin substrate 107 with the adhesive layer (ST101A). . Next, the quartz substrate 8 bonded to the support substrate 107 is carried into the dry etching apparatus 4 and the surface side of the quartz substrate 8 is dry etched (ST102A). Thereafter, the support substrate 107 is dissolved and removed (wet etching) from the quartz substrate 8 by the wet etching apparatus 5 (ST103A). Next, the quartz substrate 8 is sent to the cleaning device 6 and subjected to the cleaning process of the chemical solution, and then becomes the target of the process B. That is, the same (ST101B) to (ST103B) as the above (ST101A) to (ST103A) are executed on the back surface of the quartz substrate 8. And it is sent to the washing | cleaning apparatus 6 again, and the chemical | medical solution washing process is performed. Through the above process, the quartz substrate 8 is finely processed by dry etching, and the quartz resonator 9 is formed.

  FIG. 25 shows the bonding step executed in the above (ST101A). As shown in FIG. 25, the bonding process is performed in a vacuum atmosphere of a vacuum chamber 3a provided in the vacuum bonding apparatus 3. The support substrate 107 has a configuration in which a pressure-sensitive adhesive layer 107b similar to the pressure-sensitive adhesive layer 7b in Embodiment 1 is formed in advance on a resin substrate 107a (PET sheet). In the chamber 3a of the vacuum bonding apparatus 3, It is supplied in the state of a supply roll 114 in which a support substrate 107 with a cover film 13a having a cover tape 13a attached to the surface of the pressure-sensitive adhesive layer 107b is wound. From the support substrate 107 unwound from the supply roll 114, the cover film 13a (lower side in the figure) is peeled off by the peeling roll 15a, and is guided and collected by the guide roll 15b.

  The support substrate 107 from which the cover film 13a has been peeled is guided in the horizontal direction by the guide roller 15c. Then, the lower surface side of the pressure-sensitive adhesive layer 107 b exposed by peeling off the cover film 13 a is attached to the back surface 8 d of the crystal substrate 8. Next, the support substrate 107 is cut along a contour of the quartz substrate 8 with a cutter (not shown), so that the adhesive layer 107b of the support substrate 107 is formed on the back surface 8d of the quartz substrate 8 as shown in FIG. A workpiece 16 similar to that shown in FIG. 8 is formed. Then, as shown in FIG. 26 (b), each process shown in FIG. 13 and subsequent figures in the first embodiment is performed on the workpiece 16 with the surface 8c facing upward.

  In the first and second embodiments, an ashing process is interposed between dry etching (ST3A, 3B), (ST102A, 102B) and wet etching (ST4A, 4B), (ST103A, 103B). Also good. When the exposed portions of the pressure-sensitive adhesive layer 7b and the pressure-sensitive adhesive layer 107b are removed by this ashing process, it becomes easy for the chemical liquid to enter the bonding interface between the crystal substrate 8 and the pressure-sensitive adhesive layer 7b and the pressure-sensitive adhesive layer 107b in wet etching. The processing time required to dissolve and remove the support substrate 7 and the support substrate 107 can be shortened.

As described in detail above, the substrate dry etching method shown in the first and second embodiments is supported by the crystal substrate for the purpose of preventing damage to the crystal substrate during handling such as loading / unloading to / from the dry etching apparatus. The substrate is made of a material that can be dissolved and removed by wet etching. Thereby, the following inconveniences in the prior art using a glass plate or the like as the support substrate can be solved. That is, in the prior art, a long time (for example, 20 hours to 50 hours) is required for wet etching performed to separate the quartz substrate and the support substrate bonded together via the pressure-sensitive adhesive layer. On the other hand, in the first and second embodiments, since the support substrate itself is dissolved and removed, the time required for separating the quartz substrate can be significantly shortened (for example, 1 to 2 hours). .

  In the first and second embodiments described above, the present invention has been described by taking as an example the case where the tuning fork type crystal resonator 9 is manufactured. However, the present invention is not limited to other types of crystal resonators or crystal resonators. It can also be applied to the manufacture of crystal devices. In addition, microfabrication can also be realized by the present invention for a substrate made of a material other than quartz that is high in hardness and brittle. In addition to quartz, examples of hard and brittle materials that can realize fine processing according to the present invention include glass, quartz, sapphire, SiC, GaN, GaP, GaAs, AlN, ZnO, Si, LN (LiNbO), and LT (LiTaO). , LiGaO2, βGa2O3, YAG (Y3Al5O12), and the like. Furthermore, although the present invention has been described by taking the case of the quartz substrate 9 having a thickness of about 100 μm as an example, it is made of a hard and brittle material such as quartz, and is very thin and brittle with a thickness of, for example, 200 μm or less, particularly about 100 μm or less, Fine processing of a substrate that is likely to warp or crack due to heat due to heat can be performed by the dry etching method of the present invention.

  The substrate dry etching method of the present invention has the effect of efficiently and stably realizing microfabrication of a substrate made of a hard and brittle hard brittle material such as a quartz substrate. It can be used in fields.

1, 101 Crystal device manufacturing system 7, 107 Support substrate 7a, 107a Resin substrate 7b, 107b Adhesive layer (adhesive film)
7c conductive layer 8 crystal substrate 8b device pattern region 8c surface 8d back surface 9 crystal resonator 10a, 10b mask layer 10Pa, 10Pb device pattern part 16 work 20 chamber 22 ICP coil 24 high frequency power supply 25 substrate susceptor 29 tray 29a substrate accommodation hole 30 drive Mechanism 31 Lifting pin 32 Dielectric plate 32a Tray support surface 33, 33A, 33B, 33C Substrate support part 34 Substrate adsorption electrode 35 Metal plate 40 DC voltage application mechanism 41 DC power supply 53 High frequency application mechanism 60 Transfer arm P Plasma

Claims (9)

A vacuum vessel to which an etching gas is supplied; a plasma generation source that generates plasma by ionizing the etching gas in the vacuum vessel; and a substrate placement unit that is disposed in the vacuum vessel and on which a substrate is placed. The electrostatic chucking electrode built in the substrate mounting portion, and a heat transfer gas supply mechanism for supplying heat transfer gas to the substrate mounting surface on which the substrate is mounted in the substrate mounting portion. A dry etching method for a substrate, wherein a dry etching apparatus performs an etching process on at least one surface set as a processing surface of two surfaces forming the front and back surfaces of the substrate,
A substrate preparation step of preparing a support substrate made of a material that can be dissolved by wet etching, and having a pressure-sensitive adhesive layer that can be dissolved by wet etching on one side;
A substrate laminating step of laminating the back surface of the processed surface of the substrate to the adhesive layer of the support substrate;
The substrate having the support substrate bonded to the back surface of the processed surface is carried into a vacuum vessel of the dry etching apparatus, and the substrate is placed on the substrate mounting surface in a posture in which the processed surface of the substrate faces upward. Substrate loading process to be placed;
A substrate suction holding step of applying a DC voltage to the electrostatic chucking electrode to electrostatically chuck and hold the support substrate on the substrate mounting surface;
An etching step of etching the processed surface of the substrate by generating plasma by the plasma generation source while supplying the heat transfer gas between the substrate mounting surface and the support substrate by the heat transfer gas supply mechanism; ,
A substrate unloading step of lifting the substrate together with the support substrate from the substrate mounting surface and unloading the substrate after the etching step;
A substrate dry etching method comprising: a substrate separation step of separating only the substrate by dissolving the support substrate together with the pressure-sensitive adhesive layer by wet etching.   In the substrate bonding step, a plurality of the substrates are bonded to one support substrate, and in the substrate carry-in step, the substrate in which the support substrate is bonded to the back surface of the processed surface is placed in a vacuum container of the dry etching apparatus. 2. The substrate dry according to claim 1, wherein the substrate is placed on the substrate placement surface via the support substrate that is bonded to the substrate with the processing surface of the substrate facing upward. Etching method.   In the substrate carrying-in step, the substrate on which the support substrate is bonded to the back surface of the processed surface is held in a substrate accommodation hole of a tray provided with a substrate accommodation hole penetrating in the thickness direction, and the vacuum of the dry etching apparatus The substrate is carried into a container, and the tray is supported by a tray support portion that supports the tray, and the substrate is transferred from the tray to the substrate mounting surface with the processing surface of the substrate facing upward. The substrate dry etching method according to claim 1, wherein the substrate is dry-etched.   In the substrate bonding step, each of the substrates is bonded to one support substrate, and in the substrate carry-in step and the substrate carry-out step, each of the substrate receiving holes of the tray provided with a plurality of the substrate receiving holes is provided. 4. The method of dry etching a substrate according to claim 3, wherein the one supporting substrate is accommodated and held.   In the substrate accommodation hole, a frame-shaped support member is disposed corresponding to a support portion set in advance on the substrate, and the substrate is accommodated in the substrate accommodation hole by the support member. 5. The method for dry etching a substrate according to claim 3, wherein the substrate is supported from below via the support substrate.   In the substrate bonding step, a plurality of the substrates are bonded to one support substrate, and in the substrate carry-in step and the substrate carry-out step, a frame in which a support member is arranged corresponding to a support portion set in advance on the substrate The support substrate is held by a tray, and the substrate is placed on the substrate placement surface provided corresponding to the arrangement position of the substrate on the support substrate via the support substrate. The method of dry etching a substrate according to claim 1.   4. The substrate dry according to claim 3, wherein the substrate is raised and lowered with respect to the substrate placement surface via the tray by a plurality of raising and lowering pins provided on the substrate placement portion so as to be raised and lowered. Etching method.   In the substrate bonding step, a plurality of the substrates are bonded to one support substrate, and in the substrate carry-in step and the substrate carry-out step, a frame in which a support member is arranged corresponding to a support portion set in advance on the substrate The method of dry etching a substrate according to claim 2, wherein the support substrate is moved up and down with respect to the substrate mounting surface by a lift member having a shape.   9. The method for dry etching a substrate according to claim 1, wherein the support substrate is a substrate having a conductive layer provided on the opposite surface of the adhesive layer forming surface.

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