Processing method for quartz device and quartz device

Abstract

The invention provides a processing method for a quartz device and the quartz device. The processing method comprises the following steps: step 1, preparing a quartz wafer; 2, determining an area needing to be removed according to the quartz device needing to be obtained, and modifying the area needing to be removed on the quartz wafer by adopting laser; step 3, preparing a metal film layer on each of the upper surface and the lower surface of the quartz wafer obtained in the step 2; step 4, patterning the metal film layer, determining a quartz structure pattern which is approximately consistent with the laser modified pattern in the step 2, and exposing a region needing to be removed; step 5, preparing a second layer of mask pattern on the surface of the patterned metal film layer for determining an electrode pattern; step 6, removing an area needing to be removed by adopting a chemical solution; 7, corroding the metal film layer, and transferring the electrode pattern on the second mask layer to the metal film layer; and step 8, removing the second layer of mask. The machining precision and efficiency of the quartz structure are improved.

Description

Technical Field

[0001] The invention relates to the field of quartz devices, and in particular to a processing method for quartz devices and the quartz device. Background Art

[0002] Quartz devices are devices that use quartz crystal materials and work using the quartz piezoelectric effect and inverse piezoelectric effect. They include many actuators and sensors such as quartz crystal oscillators, quartz tuning fork gyroscopes, quartz vibration beam accelerometers, etc., and have been widely used in many fields.

[0003] Quartz devices usually require a specific processing method to produce a quartz beam structure on a quartz substrate and prepare metal electrodes on the surface or side to achieve beam resonance and signal output.

[0004] There are many methods for processing quartz structures, such as mechanical cutting, quartz wet etching, quartz dry etching, laser processing, electrochemical etching, etc. However, the mechanical cutting method has poor dimensional accuracy and cannot prepare tiny structures. The quartz dry etching method has high mask requirements and poor etching morphology, so it has not been widely used in quartz devices. The electrochemical etching method has poor technical maturity and is rarely used in quartz devices. Quartz wet etching technology is widely used in quartz devices due to its high processing accuracy and good processing repeatability. This method uses a mixed solution of hydrofluoric acid and ammonium fluoride to corrode quartz materials. However, this method is difficult to process. Due to the characteristics of quartz crystal materials, it is easy to produce unwanted crystal structures or spike defects on the side walls or etching surfaces of the structure, affecting the processing quality of the quartz structure.

[0005] In recent years, laser-induced chemical etching technology has been gradually studied, which is an improvement over quartz wet etching technology. However, if this method is applied to the processing of quartz devices, the main problem of this method is how to be compatible with the processing of quartz devices, because laser processing may damage the mask and electrode on the surface of the structure. Summary of the invention

[0006] The present invention aims to solve at least one of the technical problems existing in the prior art or related art.

[0007] To this end, the present invention provides a processing method for quartz devices and a quartz device. The processing method of the present invention introduces laser-induced chemical etching technology at a specific processing time based on the wet etching process, making it compatible with the processing of quartz devices, and will not cause damage to the mask and electrode on the surface of the structure, thereby improving the processing accuracy and efficiency of the quartz structure, thereby improving the accuracy of the quartz device and reducing the cost of the quartz device.

[0008] The technical solution of the present invention is as follows:

[0009] According to one aspect, a processing method for a quartz device is provided, the processing method comprising:

[0010] Step 1, quartz wafer preparation;

[0011] Step 2: determining the area to be removed according to the desired quartz device, and using laser to modify the area to be removed on the quartz wafer, including:

[0012] The laser scans the area to be removed in the x, y, and z directions to modify the area. There are two types of modification: one is to modify the entire area along the depth direction of the quartz wafer, and the other is to modify only to a preset depth for processing thinning structures. When scanning any area to be removed, the part of the area with a set thickness from the surface of the quartz wafer is not scanned to ensure that the quartz structure on the surface of the area is not damaged;

[0013] Step 3, preparing a metal film layer on the upper and lower surfaces of the quartz wafer obtained in step 2;

[0014] Step 4: Patterning the metal film layer to determine the quartz structure pattern, which is roughly consistent with the laser modified pattern in step 2, exposing the area to be removed;

[0015] Step 5, preparing a second mask pattern on the surface of the patterned metal film layer to determine the electrode pattern;

[0016] Step 6, using a chemical solution to remove the area to be removed, wherein the chemical solution first corrodes the unmodified area in the area to be removed, and then corrodes the modified area when the modified area is exposed, and the corrosion rate of the modified area is greater than the corrosion rate of the unmodified area;

[0017] Step 7, corroding the metal film layer, and transferring the electrode pattern on the second mask layer to the metal film layer;

[0018] Step 8: Remove the second mask layer.

[0019] Furthermore, the quartz device includes a beam, a thinning structure and a supporting structure.

[0020] Furthermore, the quartz wafer is made of quartz crystal material or fused quartz material.

[0021] Furthermore, the metal film layer is selected from any one of Cr / Au, Ti / Au, Cr / Au / Cr / Au.

[0022] Furthermore, the metal film layer patterning method in step 4 includes photolithography, etching, stripping or laser processing.

[0023] Furthermore, the second mask layer includes photoresist or Cr / Au.

[0024] Furthermore, the chemical solution includes any one of hydrofluoric acid, a mixed solution of hydrofluoric acid and ammonium fluoride, ammonium bifluoride, and sodium hydroxide.

[0025] Furthermore, in step 2, only the boundary of the area to be scanned may be scanned.

[0026] According to another aspect, a quartz device is provided. The quartz device is processed by the above method.

[0027] In the process of quartz device processing, the above technical scheme first introduces laser induction to partially modify the area that needs to be modified, avoiding the damage to the metal film layer that may be caused by the laser induced chemical corrosion scheme, thereby avoiding unexpected defects in the quartz structure. At the same time, this scheme is fully compatible with traditional wet etching process schemes, and electrodes can be processed by means of photolithography, metal corrosion, etc., with higher processing accuracy.

[0028] In the present invention, the laser modification and the traditional quartz processing process do not interfere with each other, retaining the advantage of quartz processing in preparing complex and high-precision electrodes, and achieving the optimization of fast laser-induced chemical etching speed and smooth thinning surface, while avoiding the problem of mask and electrode damage that may be caused by laser modification; the present invention can realize the processing of various complex quartz structures, including multi-layer unequal height structure processing, and can meet the processing needs of given types of quartz devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The included drawings are used to provide a further understanding of the embodiments of the present invention, which constitute a part of the specification, are used to illustrate the embodiments of the present invention, and together with the text description, explain the principles of the present invention. Obviously, the drawings in the following description are only some embodiments of the present invention, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0030] Figure 1 This is a typical schematic diagram of the cross section of quartz structure;

[0031] 1 is a quartz wafer; 11 is a beam structure; 12 is a thinning structure; 13 is a supporting structure; and 14 is an electrode.

[0032] Figure 2 It is a process flow chart of the technical solution adopted by the present invention.

[0033] 12 is a thinning structure; 14 is a metal mask; 3 is a schematic diagram of scanning laser; 4 is a laser modified area; 41 is a laser modified area above the thinning structure; and 5 is a second layer mask.

[0034] Figure 3 It is a schematic diagram of a cross section of a quartz structure.

[0035] 1 is a quartz wafer; 11 is a beam structure; 12 is a thinning structure; 13 is a supporting structure; and 14 is an electrode.

[0036] Figure 4 It is a schematic diagram of a cross section of a quartz structure.

[0037] 1 is a quartz wafer; 11 is a beam structure; 12 is a thinning structure; 13 is a supporting structure; 14 is an electrode; and 16 is a step structure.

[0038] Figure 5 This is a schematic diagram of the laser modified area of ​​a quartz structure.

[0039] 1 is a quartz wafer; 12 is a thinned structure; 15 is a peeled structure; 4 is a laser modified area; 41 is a laser modified area above the thinned structure. DETAILED DESCRIPTION

[0040] It should be noted that, in the absence of conflict, the embodiments in this application and the features in the embodiments can be combined with each other. The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present invention and its application or use. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0041] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0042] Unless otherwise specifically stated, the relative arrangement of the parts and steps described in these embodiments, numerical expressions and numerical values ​​do not limit the scope of the present invention. At the same time, it should be understood that, for ease of description, the sizes of the various parts shown in the accompanying drawings are not drawn according to the actual proportional relationship. The technology, method and equipment known to ordinary technicians in the relevant field may not be discussed in detail, but in appropriate cases, the technology, method and equipment should be regarded as a part of the authorization specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once a certain item is defined in an accompanying drawing, it does not need to be further discussed in subsequent drawings.

[0043] like Figure 1 As shown in the figure, the structure of a typical quartz device consists of four parts: resonant beam, thinning structure, support structure, and electrode. The resonant beam is the core structure of the quartz device. The thinning structure is different from other structures in the height direction and needs to be thinned through an additional corrosion process. The support structure is mainly responsible for fixing the entire quartz structure and is usually bonded or welded to the external package. The electrode is mainly used for collecting and transmitting electrical signals.

[0044] The embodiments of the present invention are directed to processing a resonant beam, a thinning structure and a supporting structure.

[0045] like Figure 2 In one embodiment of the present invention, a processing method for a quartz device is provided, the processing method comprising:

[0046] Step 1, preparing a quartz wafer 1;

[0047] Step 2: determining the area to be removed according to the desired quartz device, and modifying the area to be removed on the quartz wafer by laser, including:

[0048] The laser scans the area to be removed in the x, y and z directions to modify the area. There are two types of modification: one is that the entire area along the depth direction of the quartz wafer needs to be modified, and the other is that the area is only modified to a preset depth for processing a thinning structure. When scanning any area to be removed, the portion of the area with a set thickness away from the surface of the quartz wafer is not scanned to ensure that the quartz structure on the surface of the area is not damaged, thereby obtaining a laser modified area 4; wherein 12 is a thinning structure; 3 is a schematic diagram of scanning laser; 41 is a laser modified area above the thinning structure;

[0049] Step 3: a metal film layer 14 is prepared on the upper and lower surfaces of the quartz wafer 1 obtained in step 2; it is used as a quartz structure etching mask and electrode;

[0050] Step 4: Patterning the metal film layer 14 to determine the quartz structure pattern, which is roughly consistent with the laser modified pattern in step 2, exposing the area to be removed;

[0051] Step 5: preparing a second mask pattern on the surface of the patterned metal film layer 14 to determine the electrode pattern;

[0052] Step 6, using a chemical solution to remove the area to be removed, wherein the chemical solution first corrodes the unmodified area in the area to be removed, and then corrodes the laser modified area 4 when the laser modified area 4 is exposed, and the corrosion rate of the laser modified area 4 is greater than the corrosion rate of the unmodified area;

[0053] Step 7, corroding the metal film layer 14, transferring the electrode pattern on the second mask 5 to the metal film layer 14;

[0054] Step 8: remove the second mask layer 5.

[0055] That is, the laser processes the quartz structure to be processed by scanning in the three directions of x, y, and z. By using a suitable laser and laser parameters, the quartz crystal at the scanning position can be modified so that it has a selectivity of more than 100:1 relative to the unmodified position during the subsequent quartz wet etching process, so that it can be processed quickly without damaging other structures. Among them, there are two types of modified areas, one is the entire modification in the depth direction, and the other is only modified to a certain depth, so that the thinned structure can be processed. In the embodiment of the present invention, the laser does not scan the surface area adjacent to the quartz wafer (that is, the embodiment of the present invention partially modifies the area to be removed, and the part close to the surface of the quartz wafer is not scanned and modified), so as not to destroy the surface quartz structure, so that the quartz wafer can maintain a smooth and flat surface.

[0056] In the embodiment of the present invention, the quartz device includes a beam, a thinning structure and a supporting structure. That is, a chemical solution is used to remove the laser-modified quartz structure, thereby processing the required quartz structure, including the beam, the thinning structure, the supporting structure, etc. The unmodified area of ​​the surface will be corroded first, and the corrosion rate is slow. When the modified area is exposed, the modified area will be corroded at a very fast speed.

[0057] It can be seen that in the process of processing quartz devices, the embodiment of the present invention first introduces laser induction to partially modify the area that needs to be modified, avoiding the damage to the metal film layer that may be caused by the laser-induced chemical corrosion scheme, thereby avoiding the unexpected defects of the quartz structure. At the same time, the scheme is fully compatible with the traditional wet etching process scheme, and the electrode can be processed by means of photolithography, metal corrosion, etc., with higher processing accuracy. In the embodiment of the present invention, the laser modification and the traditional quartz processing process do not interfere with each other, retaining the advantage of quartz processing that can prepare complex and high-precision electrodes, and obtaining the optimization of laser-induced chemical corrosion with fast speed and smooth thinning surface, while avoiding the problem of mask and electrode damage that may be caused by laser modification; the embodiment of the present invention can realize the processing of various complex quartz structures, including multi-layer unequal height structure processing, which can meet the processing needs of a given type of quartz device.

[0058] According to an embodiment of the present invention, the quartz wafer 1 may be a quartz crystal material or a fused quartz material, and the cut shape, crystal orientation, and thickness of the quartz wafer 1 are not limited.

[0059] According to an embodiment of the present invention, the laser scanning area 4 in step 2 is related to the selection and parameters of the laser, and the distance between the laser scanning area 4 and the surface is not limited.

[0060] According to an embodiment of the present invention, the metal film layer 14 in step 3 includes but is not limited to Cr / Au, Ti / Au, Cr / Au / Cr / Au, etc., as long as it can meet the requirements of the corrosion mask and the electrode.

[0061] According to an embodiment of the present invention, the patterning method of the metal film layer 14 in step 4 includes but is not limited to photolithography etching, stripping, laser processing, etc.

[0062] According to an embodiment of the present invention, the second mask layer 5 in step 5 includes but is not limited to photoresist, Cr / Au, etc.

[0063] According to one embodiment of the present invention, the chemical solution in step 6 includes but is not limited to hydrofluoric acid, a mixed solution of hydrofluoric acid and ammonium fluoride, ammonium bifluoride, sodium hydroxide, etc.

[0064] In addition, the embodiments of the present invention can also be applied to more complex quartz structures, especially the thinning structure can be more complex, such as both the front and back sides need to be thinned, such as Figure 3 As shown in FIG. 1 , the corresponding process scheme requires laser scanning on the back side of the quartz wafer. The thinned structure can also include a variety of different depths, such as Figure 4 As shown, 1 is a quartz wafer; 11 is a beam structure; 12 is a thinning structure; 13 is a supporting structure; 14 is an electrode; 16 is a step structure, and only the laser scanning area needs to be controlled.

[0065] Furthermore, in step 2 of the scheme, the same processing effect can be achieved by reducing the laser scanning area, such as Figure 5 As shown, 1 is a quartz wafer; 12 is a thinning structure; 15 is a peeling structure; 4 is a laser modified area; 41 is a laser modified area above the thinning structure. It is only necessary to scan the boundary of the area to be removed. After the laser modified area 4 is corroded through, the structure to be removed 15 will automatically fall off. This method can further improve the processing efficiency.

[0066] According to another embodiment, a quartz device is provided. The quartz device is processed by the above method.

[0067] Features described and / or illustrated above for one embodiment may be used in the same or similar manner in one or more other embodiments, and / or combined with or used in place of features in other embodiments.

[0068] It should be emphasized that the term "include / comprises" when used herein refers to the presence of features, integers, steps or components, but does not exclude the presence or addition of one or more other features, integers, steps, components or combinations thereof.

[0069] The above method of the present invention can be implemented by hardware, or by hardware combined with software. The present invention relates to such a computer-readable program, which, when executed by a logic component, enables the logic component to implement the above-mentioned device or component, or enables the logic component to implement the above-mentioned various methods or steps. The present invention also relates to a storage medium for storing the above program, such as a hard disk, a magnetic disk, an optical disk, a DVD, a flash memory, etc.

[0070] The many features and advantages of these embodiments are apparent from this detailed description, and thus the appended claims are intended to cover all such features and advantages of these embodiments that fall within their true spirit and scope. Furthermore, since numerous modifications and changes will readily occur to those skilled in the art, it is not intended that the embodiments of the invention be limited to the exact construction and operation illustrated and described, but rather all suitable modifications and equivalents falling within the scope thereof are intended to be covered.

[0071] Parts of the present invention that are not described in detail are well known to those skilled in the art.

Claims

1. A processing method for a quartz device, characterized in that: The processing method comprises: Step 1, quartz wafer preparation; Step 2: determining the area to be removed according to the desired quartz device, and using laser to modify the area to be removed on the quartz wafer, including: The laser scans the area to be removed in the x, y, and z directions to modify the area. There are two types of modification: one is to modify the entire area along the depth direction of the quartz wafer, and the other is to modify only to a preset depth for processing thinning structures. When scanning any area to be removed, the part of the area that is a set thickness away from the surface of the quartz wafer is not scanned to ensure that the quartz structure on the surface of the area is not damaged; Step 3, preparing a metal film layer on the upper and lower surfaces of the quartz wafer obtained in step 2; Step 4: Patterning the metal film layer to determine the quartz structure pattern, which is roughly consistent with the laser modified pattern in step 2, exposing the area to be removed; Step 5, preparing a second mask pattern on the surface of the patterned metal film layer to determine the electrode pattern; Step 6, using a chemical solution to remove the area to be removed, wherein the chemical solution first corrodes the unmodified area in the area to be removed, and then corrodes the modified area when the modified area is exposed, and the corrosion rate of the modified area is greater than the corrosion rate of the unmodified area; Step 7, corroding the metal film layer, and transferring the electrode pattern on the second mask layer to the metal film layer; Step 8: Remove the second mask layer.

2. A processing method for a quartz device according to claim 1, characterized in that: The quartz device includes a beam, a thinning structure and a supporting structure.

3. A processing method for a quartz device according to claim 1, characterized in that: The quartz wafer is made of quartz crystal material or fused quartz material.

4. A processing method for a quartz device according to any one of claims 1 to 3, characterized in that: The metal film layer is selected from any one of Cr / Au, Ti / Au, Cr / Au / Cr / Au.

5. A processing method for a quartz device according to any one of claims 1 to 4, characterized in that: The metal film layer patterning method in step 4 includes photolithography, etching, stripping or laser processing.

6. A processing method for a quartz device according to claim 5, characterized in that: The second mask layer includes photoresist or Cr / Au.

7. A processing method for a quartz device according to claim 5, characterized in that: The chemical solution includes any one of hydrofluoric acid, a mixed solution of hydrofluoric acid and ammonium fluoride, ammonium bifluoride, and sodium hydroxide.

8. A processing method for a quartz device according to claim 1, characterized in that: In the step 2, only the boundary of the area to be scanned may be scanned.

9. A quartz device, characterized in that: The quartz device is obtained by processing using the method described in any one of claims 1 to 8.

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