CN216669766U

CN216669766U - Object stage and detection device for positioning defects

Info

Publication number: CN216669766U
Application number: CN202120819712.1U
Authority: CN
Inventors: 阙金镇; 冯淦; 赵建辉
Original assignee: Epiworld International Co ltd
Current assignee: Hantiantiancheng Electronic Technology Xiamen Co ltd
Priority date: 2021-04-21
Filing date: 2021-04-21
Publication date: 2022-06-03
Anticipated expiration: 2031-04-21

Abstract

The utility model relates to an object stage and a detection device for positioning defects, wherein the object stage for positioning defects comprises a base, a flat plate is fixed on the base, the surface of one side, away from the base, of the flat plate is defined as an upper surface, a groove is formed in the upper surface, and the shape of the groove is the same as that of an object to be detected, so that the object to be detected is accommodated; and a plurality of transverse shafts and longitudinal shafts which are perpendicular to each other are arranged on the surface of the flat plate to form a coordinate grid, and the defects of the object to be detected are positioned through the coordinate grid. The detection device of the object stage containing the positioning defects can quickly realize the identification and the positioning of the defects in the silicon carbide wafer, and can also carry out the quick defect positioning of a target coordinate area according to the detection result of a machine, thereby greatly improving the detection efficiency.

Description

Object stage and detection device for positioning defects

Technical Field

The utility model relates to a silicon carbide wafer detection technology, in particular to an object stage for positioning defects and a detection device.

Background

The silicon carbide wafer has the advantages of being several times higher than the traditional silicon in forbidden band, drift velocity, breakdown voltage, heat conductivity, high temperature resistance and the like, and has irreplaceable advantages in the electronic application fields of high temperature, high pressure, high frequency, high power, photoelectricity, radiation resistance, microwave performance and the like and in extreme environment applications of aerospace, military industry, nuclear energy and the like. Since various defects existing in silicon carbide wafers are now a limitation in material development, the study of defects in silicon carbide wafers is an important direction for improving the quality of wafers.

The existing silicon carbide wafer detection equipment such as SICA88 has limited precision, so that the morphological characteristics of defects cannot be observed well, the defect types cannot be distinguished well, manual recheck is often required after automatic detection of a machine, namely, a microscope is used for accurately observing the defects, the defect types are distinguished according to the shapes of the defects, and therefore, corresponding process optimization is carried out for feeding back to a production department.

When the defects of the silicon carbide wafer are observed by using a microscope, the defects can be identified under the amplification condition by moving the microscope head to observe different positions of the wafer one by one in a scanning mode because the defects are not different from normal wafers in color and are not directly visible by naked eyes, and the detection mode has low efficiency and is difficult to meet the industrial production requirements.

SUMMERY OF THE UTILITY MODEL

In order to solve the problems, the utility model provides an objective table for positioning defects, wherein a coordinate grid is arranged on a flat plate, after a wafer is placed in a groove on the flat plate, grid marks can be seen through the wafer due to the fact that the wafer is made of transparent materials, and therefore the position of a specific defect in the wafer is numbered, and coordinates are recorded. In subsequent detection, the approximate range of the defects can be quickly positioned according to the coordinates, because the defects of the wafers prepared by the similar processing method are concentrated in the same area on a very large probability, so that the defect identification speed is greatly improved.

In order to solve the technical problem, the utility model adopts the following scheme:

an objective table for positioning defects comprises a base, wherein a flat plate is fixed on the base, the surface of one side, away from the base, of the flat plate is defined as an upper surface, a groove is formed in the upper surface, and the shape of the groove is the same as that of an object to be detected, so that the object to be detected is accommodated; and a plurality of transverse shafts and longitudinal shafts which are perpendicular to each other are arranged on the surface of the flat plate to form a coordinate grid, and the defects of the object to be detected are positioned through the coordinate grid.

Furthermore, the object to be detected is a silicon carbide wafer, and the outer edge of the groove is closed by connecting an arc edge and a linear reference edge end to end.

Furthermore, one side of the reference edge, which is far away from the circular arc edge, is provided with a concave platform.

Furthermore, the upper surface of the flat plate is provided with an upper groove and a lower groove, the diameter of the arc edge of the upper groove is larger than that of the arc edge of the lower groove, the upper groove is positioned above the lower groove, and the bottom of the upper groove is provided with the lower groove.

Further, the coordinate grid further comprises a curve edge which is similar to the periphery of the object to be detected in graph, the curve edge is located in the orthographic projection of the groove, and the center of the curve edge is overlapped with the center of the groove.

Further, the coordinate grid is located on the upper surface of the flat plate, and the coordinate grid identifies coordinates.

Further, the flat plate is a square plate.

Further, the flat plate is a glass plate or a transparent plastic plate.

Furthermore, at least 2 limiting notches are formed in the upper surface of the flat plate, and the height of each limiting notch is lower than that of the upper surface of the flat plate; at least 2 limiting columns are fixed on the base, and the flat plate is fixed on the base by clamping the limiting notches into the limiting columns.

Based on the same inventive concept, the utility model also provides a detection device, which comprises a detection assembly and an object carrying assembly, wherein the object carrying assembly comprises the object carrying table for positioning the defects.

By adopting the technical scheme, compared with the prior art, the method can quickly realize the identification and the positioning of the defects in the silicon carbide wafer, and can also quickly position the defects in the target coordinate area according to the detection result of a machine, thereby greatly improving the detection efficiency.

Drawings

FIG. 1 is a schematic view of a stage structure for positioning defects according to embodiment 1 of the present invention;

FIG. 2 is a partial structural view of a stage for positioning defects according to embodiment 2 of the present invention;

fig. 3 is a schematic structural diagram of a stage for positioning defects according to embodiment 3 of the present invention.

Detailed Description

The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings and the detailed description, but those skilled in the art will understand that the following described embodiments are some, not all, of the embodiments of the present invention, and are only used for illustrating the present invention, and should not be construed as limiting the scope of the present invention. All other embodiments, which can be obtained by a person skilled in the art without making any creative effort based on the embodiments in the present invention, belong to the protection scope of the present invention. The examples, in which specific conditions are not specified, were conducted under conventional conditions or conditions recommended by the manufacturer. The reagents or instruments used are not indicated by the manufacturer, and are all conventional products available commercially.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

Example 1:

referring to fig. 1, the defect positioning stage includes a base (not shown in fig. 1), on which a flat plate 100 is fixed, and a surface of the flat plate 100, which is away from the base, is defined as an upper surface, and the upper surface is provided with a groove, and the shape of the groove is the same as that of an object to be detected, so as to accommodate the object to be detected; the surface of the flat plate 100 is provided with a plurality of transverse axes and longitudinal axes which are perpendicular to each other to form a coordinate grid 104, and the defects of the object to be detected are positioned through the coordinate grid 104. The grid 104 may be disposed on the upper surface or the lower surface of the plate 100.

Specifically, the object to be detected is a silicon carbide wafer, and according to the general shape of the wafer, the edge of the wafer consists of an arc and a reference edge, which is equivalent to cutting off a section of the arc by a straight line. The corresponding groove periphery is closed by connecting the circular arc edge 102 and the linear reference edge 103 end to end. In other embodiments, the shape of the groove may change to accommodate the object to be detected when the object to be detected changes.

To facilitate removal of the silicon carbide wafer, the reference edge 103 is provided with a recessed land 101 on a side thereof remote from the circular arc edge 102, preferably, the recessed land 101 has a side edge parallel to the reference edge 103.

In a specific embodiment, the following dimensions may be referenced: the flat plate is a square transparent glass plate with 24.5cm by 24.5cm, the diameter of a circular arc edge 102 is 150mm, and the length of a linear reference edge 103 is 47.5 mm. The coordinate grid 104 is filled in the whole flat plate, the horizontal axis is spaced by 2mm up and down, and the vertical axis is spaced by 2mm left and right; the horizontal axis and the vertical axis are diffused from the middle line to the upper, lower, left and right sides to form a plurality of squares. The squares are numbered, i.e. the grid coordinates, starting with the grid on the upper row of the horizontal axis center line and the grid on the right of the vertical axis center line, in the first quadrant corresponding to the xy coordinate, along the horizontal axis: from left to right: (1, 1), (2, 1), (3, 1.); from right to left: (-1, 1), (-2, 1), (-3, 1.).; along the longitudinal axis: from bottom to top: (1, 1), (1, 2), (1, 3.); from top to bottom: (1, -1), (1, -2), (1, -3.); and by analogy, the serial number is marked at the upper left corner of the square.

During detection, the wafer is placed in the groove, the defect is observed through a microscope, and the type and the coordinate of the defect are recorded. Because the positions of the defects of the wafers produced in the same batch are approximately in the same area, when a new wafer is detected, the target area can be quickly positioned according to the detected coordinates, the defects are searched in the target area, and therefore the defects are quickly identified.

Example 2:

the present embodiment is further described with reference to the detection device of a microscope. Since the stage of the microscope is already fixed at the time of its shipment. Typically includes a base (i.e., a base) with a positioning assembly for holding the viewing object. When the observation object is fixed in the clip manner, the clip is inconvenient to use because the wafer and the coordinates are covered by the clip. To address this problem, the plate 100 may be secured to the base by at least 2 retaining posts 106 secured to the base.

Referring to fig. 2, at least 2 limiting notches 105 are formed on the upper surface of the flat plate 100, and the height of the limiting notches 105 is lower than that of the upper surface of the flat plate 100; the fixing of the flat plate 100 is achieved by snapping the limiting notches 105 into the limiting posts 106, preferably by providing the limiting notches 105 at the four corners of the flat plate 100, respectively. The limiting column 106 is fixedly installed on the base at a proper height, the limiting column 106 does not need to be adjusted when the limiting column is clamped into the flat plate 100, the limiting notch 105 is pressed through the protruding part at the top of the limiting column 106, and operation is convenient.

Example 3:

referring to fig. 3, an object stage for positioning defects included in a microscope apparatus is described, which includes a base (not shown in fig. 3, corresponding to a base of a microscope), on which a flat plate 100 is fixed, and a side surface of the flat plate 100 away from the base is defined as an upper surface, and the upper surface is provided with a groove, and the shape of the groove is the same as that of an object to be detected, so as to accommodate the object to be detected; the surface of the flat plate 100 is provided with a plurality of transverse axes and longitudinal axes which are perpendicular to each other to form a coordinate grid 104, and the defects of the object to be detected are positioned through the coordinate grid 104.

Specifically, the grooves comprise an upper groove and a lower groove, the periphery of the upper groove is closed by connecting an arc edge 102 and a linear reference edge 103 end to end, and the lower groove is closed by connecting an arc edge 107 and a linear reference edge 108 end to end. The diameter of the arc edge of the upper groove is larger than that of the arc edge of the lower groove, the upper groove is positioned above the lower groove, and the bottom of the upper groove is provided with the lower groove.

An upper curve edge and a lower curve edge are respectively arranged in the orthographic projections of the upper groove and the lower groove, wherein the upper curve edge is closed by connecting an arc edge 109 and a linear reference edge 110 end to end; the lower curved edge is closed by a circular arc edge 111 and a linear reference edge 112 which are connected end to end. The shape of the curve edge is similar to that of the periphery of the object to be detected, the curve edge is positioned in the orthographic projection of the groove, and the center of the curve edge is superposed with the center of the groove. The upper curve side, the lower curve side and the square grids formed by the horizontal axis and the vertical axis form the mark together. The grid formed by the transverse axis and the longitudinal axis is mainly used for coordinate identification, the upper curve side and the lower curve side correspond to the cutting side of the wafer, and the edge of the wafer needs to be cut in actual application, so that the crystal morphology of the cutting position can be observed in advance when the defect is located, and favorable data is provided for cutting.

In order to facilitate the lens taking out, a concave platform 101 is arranged on one side of the reference edge 103 away from the circular arc edge 102, and preferably, the concave platform 101 is provided with a side edge parallel to the reference edge 103; a recess 113 is provided on the reference edge 108 on the side remote from the circular edge 107.

In a specific embodiment, the following dimensions may be referenced: the flat plate is a square transparent glass plate with 24.5cm by 24.5cm, the diameter of the circular arc edge 102 of the upper groove is 150mm, and the length of the linear reference edge 103 is 47.5 mm. The circular arc edge 107 of the lower groove has a diameter of 100mm and the linear reference edge 108 is 32.5mm long. The diameter of the circular arc edge 109 of the upper curved edge is 144mm, and the diameter of the circular arc edge 111 of the lower curved edge is 94 mm. This allows for defect detection for both size wafers.

In other embodiments, the number of grooves may be any positive integer, such as 3 or 4, and the structure may be such that two grooves, i.e., the upper groove and the lower groove in this embodiment, are in a series, so as to form a plurality of stepped arrangements.

By adopting the device, the placing positions of the wafers to be measured with the same size on the microscope objective table are uniquely fixed when the wafers are observed under the microscope at each time, so that the measured points are ensured to be the same coordinate position when the wafers are observed under the microscope, the coordinates of the defects can be accurately positioned when the defects are observed by the wafers, and the continuous improvement of the silicon carbide epitaxial growth process is promoted.

Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that variations, modifications, substitutions and alterations can be made in the above embodiments by those of ordinary skill in the art without departing from the principle and spirit of the present invention.

Claims

1. An object table for locating defects, comprising: the detection device comprises a base, wherein a flat plate is fixed on the base, the surface of one side, away from the base, of the flat plate is defined as an upper surface, a groove is formed in the upper surface, and the shape of the groove is the same as that of an object to be detected, so that the object to be detected is accommodated; and a plurality of transverse shafts and longitudinal shafts which are perpendicular to each other are arranged on the surface of the flat plate to form a coordinate grid, and the defects of the object to be detected are positioned through the coordinate grid.

2. The defect locating stage of claim 1, wherein: the object to be detected is a silicon carbide wafer, and the outer edge of the groove is closed by connecting an arc edge and a linear reference edge end to end.

3. The defect locating stage of claim 2, wherein: and one side of the reference edge, which is far away from the arc edge, is provided with a concave platform.

4. The defect locating stage of claim 2 or 3, wherein: the upper surface of the flat plate is provided with an upper groove and a lower groove, the diameter of the arc edge of the upper groove is larger than that of the arc edge of the lower groove, the upper groove is positioned above the lower groove, and the bottom of the upper groove is provided with the lower groove.

5. The defect locating stage of claim 2 or 3, wherein: the coordinate grid also comprises a curve edge which is similar to the periphery of the object to be detected in graph, the curve edge is positioned in the orthographic projection of the groove, and the center of the curve edge is superposed with the center of the groove.

6. A defect locating stage as claimed in any one of claims 1 to 3, wherein: the coordinate grid is located on the upper surface of the flat plate, and the coordinate grid identifies coordinates.

7. The defect localization object table according to any one of claims 1-3, wherein: the flat plate is a square plate.

8. A defect locating stage as claimed in any one of claims 1 to 3, wherein: the flat plate is a glass plate or a transparent plastic plate.

9. A defect locating stage as claimed in any one of claims 1 to 3, wherein: the upper surface of the flat plate is provided with at least 2 limiting notches, and the height of each limiting notch is lower than that of the upper surface of the flat plate; at least 2 limiting columns are fixed on the base, and the flat plate is fixed on the base by clamping the limiting notches into the limiting columns.

10. A detection device, characterized by: comprising an inspection assembly and a carrier assembly comprising a defect locating stage according to any one of claims 1 to 9.