Surface wave filter interdigital strip tail end compensation structure

Abstract

The utility model relates to the technical field of surface acoustic wave devices, in particular to a surface wave filter interdigital strip tail end compensation structure, which comprises square parts symmetrically arranged at the tail ends of interdigital strips, each square part is provided with a transverse edge and a longitudinal edge which are adjacent to each other, the transverse edge is connected with a longitudinal extension part, the longitudinal edge is connected with a transverse extension part, and the transverse extension part is connected with a surface acoustic wave filter. According to the utility model, the gap between the square part and the interdigital strip in the prior art is filled, the edge of the tail end of the interdigital strip changes gently under the action of an optical proximity effect during photoetching, the effect of compensating the tail end of the interdigital strip is achieved, spurious signals are also prevented from being generated, and the accuracy of photoetching is improved. By adding the compensation pattern at the tail end of the finger strip of the mask, the Q value and the bandwidth of a product are effectively improved, and the performance of the product is further improved.

Description

Technical Field

[0001] The utility model relates to the technical field of surface acoustic wave devices, in particular to a surface wave filter interdigitated strip terminal compensation structure. Background Art

[0002] Surface acoustic wave devices are devices that use surface acoustic waves to simulate electrical signals, mainly including surface acoustic wave resonators and surface acoustic wave filters and other related devices. Its main transducer unit is called an interdigital transducer. In order to suppress the waveguide mode, a false finger is often designed at the bus bar end of the interdigital transducer. The interdigital transducer is completed by transferring the image on the mask to the piezoelectric wafer through semiconductor processes including coating and photolithography, and then the device is manufactured through processes such as scribing, chip mounting, lead welding, and packaging. During the photolithography process, due to the influence of the optical proximity effect, the edge of the finger end is distorted and becomes rounded. The rounded edge may cause tip discharge and affect product performance. For finger end compensation, the conventional method is to add only square compensation at the end, such as Figure 2 However, due to reasons such as the process control of lithography, tiny steps are often formed at the ends of the fingers, similar to end weighting, forming new stray signals. Utility Model Content

[0003] The purpose of the utility model is to solve the above technical problem and to provide a surface wave filter interdigital strip end compensation structure.

[0004] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0005] A surface wave filter interdigital strip end compensation structure is designed, comprising a square portion symmetrically arranged at the end of the interdigital strip, the square portion having adjacent lateral edges and longitudinal edges, the lateral edges being connected to longitudinal extension portions, the longitudinal edges being connected to lateral extension portions, and two opposite lateral extension portions being connected via a connecting portion.

[0006] Furthermore, the width of the longitudinal extension portion gradually decreases in a direction away from the transverse edge.

[0007] Furthermore, the shape of the longitudinal extension portion is a right triangle.

[0008] Furthermore, the width of the transverse extension portion gradually decreases from the longitudinal edge toward the connecting portion.

[0009] Furthermore, the shape of the lateral extension portion is a right triangle.

[0010] Furthermore, the longitudinal extension portion has a longitudinal right-angled side, the transverse extension portion has a transverse right-angled side, and the longitudinal right-angled side and the transverse right-angled side are connected and perpendicular to each other.

[0011] The utility model proposes a surface wave filter finger-end compensation structure, which has the beneficial effect that: the utility model fills the gap between the square part and the finger-end in the prior art, and under the action of the optical proximity effect during lithography, the edge of the finger-end will change smoothly, so as to achieve the effect of compensating the finger-end and avoid the generation of stray signals. By adding compensation patterns at the finger-end of the mask, the Q value and bandwidth of the product are effectively improved, and the performance of the product is further improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a schematic diagram of the structure of the utility model;

[0013] Figure 2 It is a schematic diagram of the interdigitated strip compensation structure in the prior art;

[0014] Figure 3 This is a schematic diagram of the distortion at the end of the interdigitated strip;

[0015] Figure 4 It is a schematic diagram of the interdigitated strip;

[0016] Figure 5 It is an enlarged schematic diagram of the compensation structure of the utility model; DETAILED DESCRIPTION

[0017] The technical solutions in the embodiments of the present invention will be described clearly and completely 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, rather than all of the embodiments.

[0018] Reference Figure 1-5 An embodiment of the novel invention is disclosed, which discloses a surface wave filter interdigitated strip end compensation structure, including a square portion 2 symmetrically arranged at the end 1 of the interdigitated strip, the square portion 2 having adjacent lateral edges 201 and longitudinal edges 202, the lateral edges 201 being connected to the longitudinal extension portions 3, the longitudinal edges 202 being connected to the lateral extension portions 4, and the two opposite lateral extension portions 4 being connected by a connecting portion 5.

[0019] The utility model fills the gap between the square part and the interdigitated strip in the prior art by providing a longitudinal extension part 3 and a transverse extension part 4. During photolithography, under the action of the optical proximity effect, the edge of the end of the interdigitated strip will change smoothly, thereby achieving the effect of compensating the end of the finger and avoiding the generation of stray signals. By adding a compensation pattern at the end of the mask finger, the Q value and bandwidth of the product are effectively improved, thereby further improving the performance of the product.

[0020] In an optional embodiment of the utility model, the width of the longitudinal extension portion 3 gradually decreases in the direction away from the lateral edge 201, and the shape of the longitudinal extension portion 3 is a right triangle. During photolithography, due to the optical proximity effect, the light intensity gradually decreases from the end of the finger to the direction away from the lateral edge 201, and the final finger edge tends to be a straight line.

[0021] In an optional embodiment of the utility model, the width of the lateral extension portion 4 gradually decreases from the longitudinal edge 202 toward the connecting portion 5, and the shape of the lateral extension portion 4 is a right triangle. During photolithography, due to the optical proximity effect, the light intensity gradually decreases from the end edge of the finger toward the direction away from the lateral edge 202, resulting in a final finger end face tending to a straight line.

[0022] In an optional embodiment of the utility model, the longitudinal extension portion 3 has a longitudinal right-angled edge 301, and the transverse extension portion 4 has a transverse right-angled edge 401. The longitudinal right-angled edge 301 and the transverse right-angled edge 401 are connected and perpendicular to each other. When the transverse and longitudinal light intensity changes of the optical proximity effect are consistent during lithography, it is ensured that the final finger end face tends to a right angle.

[0023] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes within the technical scope disclosed by the present invention according to the technical scheme and the utility model concept of the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A surface wave filter interdigital strip end compensation structure, comprising a square portion (2) symmetrically arranged at the end of the interdigital strip (1), characterized in that: The square portion (2) has adjacent transverse edges (201) and longitudinal edges (202); the transverse edges (201) are connected to longitudinal extension portions (3); the longitudinal edges (202) are connected to transverse extension portions (4); and two opposite transverse extension portions (4) are connected via a connecting portion (5).

2. A surface wave filter interdigital strip end compensation structure according to claim 1, characterized in that: The width of the longitudinal extension portion (3) gradually decreases in a direction away from the transverse edge (201).

3. A surface wave filter interdigital strip end compensation structure according to claim 2, characterized in that: The shape of the longitudinal extension portion (3) is a right triangle.

4. A surface wave filter interdigital strip end compensation structure according to claim 1, characterized in that: The width of the transverse extension portion (4) gradually decreases in a direction from the longitudinal edge (202) to the connecting portion (5).

5. A surface wave filter interdigital strip end compensation structure according to claim 4, characterized in that: The transverse extension portion (4) is in the shape of a right triangle.

6. The surface wave filter interdigital strip end compensation structure according to claim 1, characterized in that: The longitudinal extension portion (3) has a longitudinal right-angled side (301), and the transverse extension portion (4) has a transverse right-angled side (401). The longitudinal right-angled side (301) and the transverse right-angled side (401) are connected and perpendicular to each other.

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