Flow guiding device of near-surface resistance tester

Abstract

The utility model provides a flow guide device of a near-surface resistance tester. The flow guide device comprises a shell, an upper cover and a flow guide plate, the shell comprises a first side plate, a second side plate, a third side plate, a fourth side plate and a bottom plate; the guide plate is fixed in the oxidation cavity, one end of the guide plate is attached to the inner wall of the second side plate, the other end of the guide plate is attached to the inner wall of the fourth side plate, and the lower surface of the guide plate is attached to the inner wall of the bottom plate. When the resistance of the epitaxial layer on the surface of the wafer is measured, CDA enters the oxidation cavity from the air inlet and is blocked by the flow guide plate, and the CDA is blown to the upper surface of the whole wafer from the side surface and the top surface, close to the air inlet, of the flow guide plate, so that the air flow on the surface of the wafer can be distributed more uniformly, and the density and the thickness of the oxide layer on the surface of the wafer are more uniform; and the finally measured resistance value is more accurate and stable.

Description

Technical Field

[0001] The utility model relates to the technical field of near-surface resistance testers, in particular to a flow guiding device of a near-surface resistance tester. Background Art

[0002] In the wafer manufacturing process, a near-surface resistance tester is needed to measure the resistance of the epitaxial layer on the wafer surface. A near-surface resistance tester is also called a surface resistance tester. The structure of a near-surface resistance tester is as follows: Figure 1 As shown, it includes a shell 1, an upper cover 2 and an ultraviolet lamp 5; the shell 1 includes a first side plate 11, a second side plate 12, a third side plate 13, a fourth side plate 14 and a bottom plate 15, the first side plate 11 is provided with an air inlet 111, and the third side plate 13 is provided with an air outlet 131; one end of the upper cover 2 is hingedly connected to the top end of the second side plate 12, the upper cover 2 and the shell 1 are enclosed to form an oxidation chamber, and the upper cover 2 can be opened and closed relative to the shell 1; the ultraviolet lamp 5 is installed on the inner side of the upper cover 2.

[0003] When measuring the resistance of the epitaxial layer on the surface of wafer 4, wafer 4 needs to be placed in an oxidation chamber and CDA (Clean Dry Air) is input from the air inlet 111. The oxygen in CDA generates ozone under ultraviolet radiation, and the ozone reacts with the silicon on the surface of wafer 4 to generate an oxide layer. The density and thickness of the oxide layer affect the measurement result of the resistance.

[0004] However, the line between the air inlet 111 and the air outlet 131 is usually aligned with the center line of the wafer 4. When CDA flows through the air inlet 111, the oxidation chamber and the air outlet 131, the airflow distribution on the surface of the wafer 4 is uneven, the oxygen concentration in the middle position of the wafer 4 is high, and the oxygen concentration at the edge position is low, which causes the oxide layer on the surface of the wafer 4 to be unevenly distributed, and the final measured resistance value is inaccurate. Utility Model Content

[0005] The utility model provides a flow guiding device for a near-surface resistance tester to solve the technical problem of uneven airflow distribution on the surface of a wafer.

[0006] In order to solve the above technical problems, the utility model provides a flow guide device for a near-surface resistance tester, comprising a shell, an upper cover and a flow guide plate; the shell comprises a first side plate, a second side plate, a third side plate, a fourth side plate and a bottom plate, the first side plate, the second side plate, the third side plate and the fourth side plate are connected in sequence, the first side plate is provided with an air inlet, and the third side plate is provided with an air outlet; one end of the upper cover is hingedly connected to the top end of the second side plate, the upper cover and the shell are enclosed to form an oxidation chamber, and the upper cover can be opened and closed relative to the shell;

[0007] The guide plate is fixed in the oxidation chamber, one end of the guide plate is in contact with the inner wall of the second side plate, the other end of the guide plate is in contact with the inner wall of the fourth side plate, and the lower surface of the guide plate is in contact with the inner wall of the bottom plate.

[0008] Optionally, there is a gap between the guide plate and the inner wall of the first side plate.

[0009] Optionally, the height of the guide plate is lower than the height of the first side plate, and higher than the height of the air inlet relative to the bottom plate.

[0010] Optionally, the surface of the guide plate is a smooth surface.

[0011] Optionally, a width of a gap between the guide plate and an inner wall of the first side plate is a, and a satisfies 0<a<1 cm.

[0012] Optionally, the guide plate is in the shape of a prism.

[0013] Optionally, the guide plate is in the shape of a cuboid.

[0014] Optionally, the guide plate is in the shape of a cylinder.

[0015] Optionally, the axes of the air inlet and the air outlet are on the same straight line.

[0016] The utility model provides a flow guide device for a near-surface resistance tester, which includes a flow guide plate. When measuring the resistance of an epitaxial layer on a wafer surface, CDA enters an oxidation chamber from an air inlet and is blocked by the flow guide plate. CDA is blown from the side and top surfaces of the flow guide plate close to the air inlet to the upper surface of the entire wafer, so that the airflow distribution on the wafer surface can be more uniform, thereby making the density and thickness of the oxide layer on the wafer surface more uniform, and the resistance value finally measured is more accurate and stable. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 The present invention is a schematic diagram of the structure after a wafer is placed in a near-surface resistance tester in the prior art.

[0018] Figure 2 The utility model is provided in an embodiment of a near-surface resistance tester after placing a wafer in the structure schematic diagram.

[0019] Figure 3 It is a structural schematic diagram of a guide plate provided in one embodiment of the utility model.

[0020] Figure 4 It is a structural schematic diagram of a guide plate provided in one embodiment of the utility model.

[0021] [Description of reference numerals is as follows]:

[0022] Shell-1, upper cover-2, guide plate-3, wafer-4, ultraviolet lamp-5;

[0023] A first side plate 11, a second side plate 12, a third side plate 13, a fourth side plate 14, and a bottom plate 15;

[0024] Air inlet - 111;

[0025] Air outlet - 131;

[0026] Width of the gap - a. DETAILED DESCRIPTION

[0027] In order to make the purpose, advantages and features of the utility model clearer, the following is a further detailed description of a flow guide device for a near-surface resistance tester proposed by the utility model in conjunction with the accompanying drawings. It should be noted that the accompanying drawings are all in a very simplified form and are not in precise proportions, and are only used to conveniently and clearly assist in explaining the purpose of the embodiments of the utility model.

[0028] In the description of the present invention, the terms "first", "second", etc. are added for the convenience of description and reference, and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined by the terms "first", "second", etc. may explicitly or implicitly include one or more of the features.

[0029] like Figure 2 As shown, the present embodiment provides a flow guide device for a near-surface resistance tester, comprising a shell 1, an upper cover 2 and a flow guide plate 3; the shell 1 comprises a first side plate 11, a second side plate 12, a third side plate 13, a fourth side plate 14 and a bottom plate 15, the first side plate 11, the second side plate 12, the third side plate 13 and the fourth side plate 14 are connected in sequence, the first side plate 11 is provided with an air inlet 111, and the third side plate 13 is provided with an air outlet 131; one end of the upper cover 2 is hingedly connected to the top end of the second side plate 12, the upper cover 2 and the shell 1 are enclosed to form an oxidation chamber, and the upper cover 2 can be opened and closed relative to the shell 1; the flow guide plate 3 is fixed in the oxidation chamber, one end of the flow guide plate 3 is in contact with the inner wall of the second side plate 12, the other end of the flow guide plate 3 is in contact with the inner wall of the fourth side plate 14, and the lower surface of the flow guide plate 3 is in contact with the inner wall of the bottom plate 15.

[0030] A flow guide device of a near-surface resistance tester provided in this embodiment includes a flow guide plate 3. When measuring the resistance of the epitaxial layer on the surface of the wafer 4, CDA enters the oxidation chamber from the air inlet 111 and is blocked by the flow guide plate 3. CDA is blown from the side and top surface of the flow guide plate 3 close to the air inlet 111 to the upper surface of the entire wafer 4. This can make the airflow distribution on the surface of the wafer 4 more uniform, and thus make the density and thickness of the oxide layer on the surface of the wafer 4 more uniform, and the finally measured resistance value is more accurate and stable.

[0031] Optional, such as Figure 2 As shown, there is a gap between the guide plate 3 and the inner wall of the first side plate 11, which facilitates the installation of the guide plate 3. In other embodiments, the middle and lower parts of the guide plate 3 can also be connected to the inner wall of the first side plate 11, but the connecting part of the two cannot cover the air inlet 111.

[0032] Optional, such as Figure 2 As shown, the height of the guide plate 3 is lower than the height of the first side plate 11, and higher than the height of the air inlet 111 relative to the bottom plate 15, so that the guide effect of the guide plate 3 can be improved, and the air flow distribution on the surface of the wafer 4 can be more uniform. In other embodiments, the height of the guide plate 3 can be equal to the height of the air inlet 111 relative to the bottom plate 15.

[0033] Optional, such as Figure 2-Figure 4 As shown, the surface of the guide plate 3 is a smooth surface. The smooth surface means that the surface of the guide plate 3 is similar to a mirror surface, and there are no protrusions or pits on the surface of the guide plate 3. The smooth surface can reduce the resistance of the airflow and make the airflow flow more smoothly.

[0034] Optional, such as Figure 2 As shown, the width of the gap between the guide plate 3 and the inner wall of the first side plate 11 is a, and a satisfies 0<a<1cm. The wafer 4 needs to be placed in the oxidation chamber. If a is set to be small, the size of the original shell 1 can be unchanged; if a is set to be too large, the size of the original shell 1 needs to be changed.

[0035] Optional, such as Figure 2 and Figure 3 As shown, the guide plate 3 is prism-shaped, which is convenient for processing to form the guide plate 3. In other embodiments, the guide plate 3 may be irregular in shape, but the side and top surfaces of the guide plate 3 close to the air inlet 111 need to be smooth surfaces so that the CDA is subject to less resistance.

[0036] Optional, such as Figure 2 As shown, the guide plate 3 is in the shape of a cuboid, which makes it convenient to process and form the guide plate 3.

[0037] Optional, such as Figure 4 As shown, the guide plate 3 is in the shape of a cylinder, which makes it convenient to process and form the guide plate 3.

[0038] Optional, reference Figure 2 As shown, the guide plate 3 is fixed to the bottom plate 15 by screws, which facilitates the installation and fixing of the guide plate 3. In other embodiments, the guide plate 3 can be fixed to the bottom plate 15 by glue.

[0039] Optional, such as Figure 2 As shown, the shape of the oxidation chamber is a cuboid, which is convenient for processing to form the shell 1. In other embodiments, the shape of the oxidation chamber can be cylindrical or other shapes.

[0040] Optional, such as Figure 2 As shown, the upper cover 2 is in the shape of a cuboid, which facilitates processing to form the upper cover 2. In other embodiments, the upper cover 2 may be in the shape of a disc or other shapes.

[0041] Optional, such as Figure 2 As shown, the air inlet 111 and the air outlet 131 are both circular in shape, which makes it convenient for the air inlet 111 and the air outlet 131 to be connected to the gas pipeline.

[0042] Optional, such as Figure 2 As shown, the axes of the air inlet 111 and the air outlet 131 are in the same straight line, which reduces the resistance encountered by the CDA in the oxidation chamber.

[0043] Optional, such as Figure 2 As shown, the guide plate 3 is made of carbon fiber or polymer material, so that the guide plate 3 has a higher hardness.

[0044] To sum up, the utility model provides a flow guide device for a near-surface resistance tester, which includes a flow guide plate 3. When measuring the resistance of the epitaxial layer on the surface of the wafer 4, CDA enters the oxidation chamber from the air inlet 111 and is blocked by the flow guide plate 3. CDA is blown from the side and top surface of the flow guide plate 3 close to the air inlet 111 to the upper surface of the entire wafer 4. This can make the airflow distribution on the surface of the wafer 4 more uniform, and thus make the density and thickness of the oxide layer on the surface of the wafer 4 more uniform, and the finally measured resistance value is more accurate and stable.

[0045] The above description is only a description of the preferred embodiment of the utility model, and is not any limitation to the scope of the utility model. Any changes and modifications made by ordinary technicians in this field based on the above disclosure are within the protection scope of the utility model.

Claims

1. A flow guide device for a near-surface resistance tester, characterized in that: It comprises a shell, an upper cover and a guide plate; the shell comprises a first side plate, a second side plate, a third side plate, a fourth side plate and a bottom plate, the first side plate, the second side plate, the third side plate and the fourth side plate are connected in sequence, the first side plate is provided with an air inlet, and the third side plate is provided with an air outlet; one end of the upper cover is hingedly connected to the top end of the second side plate, the upper cover and the shell are enclosed to form an oxidation chamber, and the upper cover can be opened and closed relative to the shell; The guide plate is fixed in the oxidation chamber, one end of the guide plate is in contact with the inner wall of the second side plate, the other end of the guide plate is in contact with the inner wall of the fourth side plate, and the lower surface of the guide plate is in contact with the inner wall of the bottom plate.

2. A flow guiding device for a near-surface resistance tester as claimed in claim 1, characterized in that: A gap is defined between the guide plate and the inner wall of the first side plate.

3. A flow guiding device for a near-surface resistance tester as claimed in claim 1, characterized in that: The height of the guide plate is lower than the height of the first side plate, and is higher than the height of the air inlet relative to the bottom plate.

4. A flow guiding device for a near-surface resistance tester as claimed in claim 1, characterized in that: The surface of the guide plate is a smooth surface.

5. A flow guiding device for a near-surface resistance tester as claimed in claim 2, characterized in that: A width of a gap between the guide plate and the inner wall of the first side plate is a, and a satisfies 0<a<1 cm.

6. A flow guiding device for a near-surface resistance tester as claimed in claim 4, characterized in that: The guide plate is in the shape of a prism.

7. A flow guiding device for a near-surface resistance tester as claimed in claim 6, characterized in that: The guide plate is in the shape of a cuboid.

8. A flow guiding device for a near-surface resistance tester as claimed in claim 4, characterized in that: The guide plate is in the shape of a cylinder.

9. The flow guiding device of the near-surface resistance tester according to claim 1, characterized in that: The axes of the air inlet and the air outlet are on the same straight line.

Images