Epitaxial surface defect failure analysis tool for COS chip

Abstract

The utility model discloses a COS chip epitaxy surface defect failure analysis tool, which comprises a positioning substrate and an objective table, the top of the positioning substrate is fixedly provided with a mounting shell, the mounting shell is internally provided with a translation assembly used for adjusting the position of the objective table in the horizontal direction, the objective table is arranged at the moving end of the translation assembly, and the objective table is arranged at the moving end of the translation assembly. A cavity is formed in the objective table, a COS chip placed on the upper surface of the objective table can be clamped and positioned through cooperative use of the adjusting assembly, the connecting block and the clamping block, the clamped and positioned COS chip can be polished and ground through the grinding assembly, and the position of the COS chip on the objective table can be adjusted in the horizontal direction through the translation assembly. According to the COS chip abnormal point detection device, special failure analysis equipment does not need to be used for analysis, abnormal phenomena can be found out more quickly and better, and meanwhile analysis cost is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of chip surface defect analysis, in particular to an epitaxial surface defect failure analysis tool for a COS chip. Background Art

[0002] With the continuous development of science and technology, chip manufacturing has become a core part of the modern electronic industry. Among them, COS chips (also known as flip-chip chips) have been widely used in many fields due to their unique packaging form and superior performance. During the manufacturing process, due to various reasons, defects may appear on the epitaxial surface of COS chips, which may cause the failure of chip performance. Therefore, failure analysis of the epitaxial surface defects of COS chips is crucial.

[0003] In the process of improving the process quality of semiconductor chips, finding out the root cause of chip failure is an initial step that must be taken. Since special failure analysis equipment is currently required for analysis, the cost of failure analysis equipment is relatively high. Therefore, we need to propose a COS chip epitaxial surface defect failure analysis tool. Utility Model Content

[0004] The utility model aims to provide a COS chip epitaxial surface defect failure analysis tool, aiming to solve the problem that special failure analysis equipment is needed for analysis in the prior art, and the cost of the failure analysis equipment is relatively high.

[0005] In order to achieve the above purpose, the utility model provides the following technical solutions:

[0006] A tool for failure analysis of epitaxial surface defects of a COS chip comprises a positioning substrate and a stage, wherein a mounting shell is fixedly mounted on the top of the positioning substrate, a translation assembly for adjusting the position of the stage in a horizontal direction is arranged inside the mounting shell, the stage is arranged at the moving end of the translation assembly, a cavity is arranged inside the stage, two groups of through grooves are symmetrically opened on the top of the stage, connecting blocks are slidably connected inside the two groups of through grooves, clamping blocks are fixedly connected on the tops of the two groups of connecting blocks, an adjustment assembly for adjusting the distance between the two groups of clamping blocks is arranged inside the cavity, a metallographic microscope is fixedly mounted on one side of the upper surface of the positioning substrate, a molding frame is fixedly mounted on the top of the positioning substrate, and a polishing assembly for polishing a COS chip is arranged on the top of the molding frame.

[0007] Preferably, the translation assembly includes a ball screw, both ends of which are rotatably mounted on the inner walls of both sides of the mounting shell, one end of the ball screw passes through the mounting shell and is connected to a driving motor, a driving block is threadedly connected to the outer wall of the ball screw, a T-block is fixedly mounted on the top of the driving block, and the stage is fixedly mounted on the top of the T-block.

[0008] Preferably, the driving block is located on both sides of the ball screw and is slidably plugged with guide rods, and both ends of the two groups of guide rods are fixedly connected to the inner walls of the mounting shell on both sides.

[0009] Preferably, the drive motor is fixedly mounted on a side wall of the mounting shell, and one end of the output shaft of the drive motor is fixedly connected to one end of the ball screw.

[0010] Preferably, the adjustment assembly includes a worm, one end of which is rotatably mounted on an inner wall of one side of the cavity, one end of the worm passes through the stage and is fixedly connected to a handwheel, the top of the worm is meshed with a worm wheel, a bidirectional lead screw is fixedly inserted inside the worm wheel, and two groups of adjustment blocks are symmetrically threaded on the outer wall of the bidirectional lead screw, and the two groups of connecting blocks are respectively fixedly connected to the tops of the two groups of adjustment blocks.

[0011] Preferably, the inner top of the cavity is fixedly connected with a rotating seat, one end of the worm is rotatably mounted on a side wall of the rotating seat, and both ends of the bidirectional screw are rotatably mounted on two side inner walls of the cavity respectively.

[0012] Preferably, the polishing assembly includes an electric push rod, which is fixedly installed on the top of the mold frame. One end of the telescopic end of the electric push rod passes through the mold frame and is fixedly connected to a lifting plate, and the bottom of the lifting plate is fixedly connected to the polishing device body.

[0013] Preferably, four groups of L-shaped limit members are fixedly mounted on the top of the mounting shell, and the four groups of L-shaped limit members are symmetrically arranged in pairs.

[0014] Compared with the prior art, the beneficial effects of the utility model are:

[0015] The utility model does not need to use special failure analysis equipment for analysis, can find abnormal phenomena faster and better, and at the same time, reduces the analysis cost. By setting the adjustment component, the connection block and the clamping block, the COS chip placed on the upper surface of the stage can be clamped and positioned, by setting the polishing component, the clamped and positioned COS chip can be polished and polished, by setting the translation component, the COS chip on the stage can be adjusted in the horizontal direction, so that the polished COS chip can be moved under the metallographic microscope to preliminarily confirm the position of the abnormal point. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a structural schematic diagram of the utility model;

[0017] Figure 2 It is a structural schematic diagram of the translation assembly and the stage of the utility model;

[0018] Figure 3 It is a structural schematic diagram of the adjustment component of the utility model;

[0019] Figure 4 It is a structural schematic diagram of the grinding assembly of the utility model.

[0020] In the figure: 1. positioning substrate; 2. stage; 3. mounting shell; 4. translation assembly; 401. ball screw; 402. drive motor; 403. drive block; 404. T-block; 5. cavity; 6. through slot; 7. connecting block; 8. clamping block; 9. adjustment assembly; 901. worm; 902. hand wheel; 903. worm gear; 904. bidirectional screw; 905. adjustment block; 10. metallographic microscope; 11. profiling frame; 12. polishing assembly; 1201. electric push rod; 1202. lifting plate; 1203. polishing device body; 13. guide rod; 14. rotating seat; 15. L-shaped limiter. DETAILED DESCRIPTION

[0021] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0022] See also Figure 1-4 , the utility model provides a technical solution:

[0023] A COS chip epitaxial surface defect failure analysis tool comprises a positioning substrate 1 and a stage 2, a mounting shell 3 is fixedly mounted on the top of the positioning substrate 1, a translation assembly 4 for adjusting the horizontal position of the stage 2 is arranged inside the mounting shell 3, the stage 2 is arranged at the moving end of the translation assembly 4, a cavity 5 is arranged inside the stage 2, two groups of through grooves 6 are symmetrically opened on the top of the stage 2, connection blocks 7 are respectively slidably connected inside the two groups of through grooves 6, and clamps are respectively fixedly connected on the tops of the two groups of connection blocks 7. The block 8 is provided inside the cavity 5 with an adjusting component 9 for adjusting the distance between the two groups of clamping blocks 8, a metallographic microscope 10 is fixedly installed on one side of the upper surface of the positioning substrate 1, a mold frame 11 is fixedly installed on the top of the positioning substrate 1, and a polishing component 12 for polishing the COS chip is provided on the top of the mold frame 11. The utility model can analyze the surface of the epitaxial layer of the COS chip quickly, efficiently and at low cost, and can make a preliminary judgment on whether there are defects on the epitaxial surface of the COS chip through visual inspection and analysis after sample preparation;

[0024] The translation assembly 4 includes a ball screw 401, both ends of which are rotatably mounted on the inner walls of the mounting shell 3, one end of the ball screw 401 passes through the mounting shell 3 and is connected to a driving motor 402, a driving block 403 is threadedly connected to the outer wall of the ball screw 401, a T-block 404 is fixedly mounted on the top of the driving block 403, and the stage 2 is fixedly mounted on the top of the T-block 404;

[0025] The driving block 403 is located on both sides of the ball screw 401 and is slidably connected with guide rods 13. The two ends of the two sets of guide rods 13 are respectively fixedly connected to the inner walls of the mounting shell 3 on both sides. By setting the guide rods 13, the driving block 403 is limited, so that the driving block 403 is more stable during operation.

[0026] The driving motor 402 is fixedly mounted on a side wall of the mounting shell 3, one end of the output shaft of the driving motor 402 is fixedly connected to one end of the ball screw 401, and the driving motor 402 is configured as a forward and reverse stepping motor;

[0027] The adjustment assembly 9 includes a worm 901, one end of which is rotatably mounted on an inner wall of one side of the cavity 5, one end of which passes through the stage 2 and is fixedly connected to a handwheel 902, a worm wheel 903 is meshed on the top of the worm 901, a bidirectional lead screw 904 is fixedly inserted inside the worm wheel 903, two groups of adjustment blocks 905 are symmetrically threaded on the outer wall of the bidirectional lead screw 904, and two groups of connection blocks 7 are fixedly connected to the tops of the two groups of adjustment blocks 905 respectively;

[0028] The inner top of the cavity 5 is fixedly connected with a rotating seat 14, one end of the worm 901 is rotatably mounted on one side wall of the rotating seat 14, and the two ends of the bidirectional screw 904 are rotatably mounted on the inner walls of both sides of the cavity 5 respectively;

[0029] The polishing assembly 12 includes an electric push rod 1201, which is fixedly installed on the top of the mold frame 11. One end of the telescopic end of the electric push rod 1201 passes through the mold frame 11 and is fixedly connected to a lifting plate 1202. The bottom of the lifting plate 1202 is fixedly connected to a polishing device body 1203. The utility model uses HF acid solution to prepare samples. A certain amount of HF acid solution (HF solution concentration of about 20%) is added to a plastic solvent, and the sampled COS chip is placed in the solution. After the COS chip is separated from the P-side electrode, the operation is performed. The operation is more convenient and can completely get rid of the traditional grinding COS chip analysis method: first, it does not need to be affected by the small size of COS, the sample is not easy to fix, and the difficulty of ensuring the required level of the COS grinding surface is required; second, it avoids the difficulty of ensuring that the sample is not mechanically damaged during the grinding process; third, during the production process, it avoids the COS chip from being subjected to stress, thereby causing factors of change; finally, the utility model adds a polishing process to ensure the integrity of the COS chip epitaxial layer failure analysis sample preparation method;

[0030] The surface layer of the COS chip is polished until the surface of the epitaxial structure layer that we want to analyze is reached, and then the surface is cleaned. Finally, the chip surface is analyzed by visual inspection using a metallographic microscope 10 in the bright and dark fields (e.g., if only the contact layer needs to be analyzed, the COS chip is first stripped by solution, and the surface is cleaned after micro-polishing the COS chip, and then the surface state of the epitaxial layer can be visually inspected and analyzed. If the inner layer such as the cladding or waveguide layer needs to be analyzed, thin and polish it first, and then clean the surface for visual inspection and analysis. In general, the COS chip is polished to the cladding, and then cleaned for visual inspection and analysis). The microscope visual inspection and analysis action is just a more clear visual inspection and analysis of the existing state of the epitaxial layer surface itself, such as: whether there are abnormalities in density distribution, defect points, high temperature points, etc. The microscope will not change the characteristics of the COS chip surface. The abnormal characteristic points on the surface of the COS chip epitaxial layer can be further confirmed by SEM electron microscope scanning (not shown in the figure) and energy spectrum element composition comparison analysis;

[0031] Four groups of L-shaped limit members 15 are fixedly installed on the top of the mounting shell 3. The four groups of L-shaped limit members 15 are symmetrically arranged in pairs. The top of the T-block 404 is clamped in the inner cavity of the L-shaped limit member 15 to position the stage 2, thereby ensuring that the stage 2 can be located directly below the polishing device body 1203 or the metallographic microscope 10.

[0032] Working principle: When the utility model is used, a COS chip is placed on the upper surface of the stage 2. By rotating the hand wheel 902, the worm 901 can be driven to rotate, thereby driving the worm wheel 903 to rotate, and then driving the bidirectional screw 904 to rotate, so that the distance between the two groups of adjustment blocks 905 can be adjusted, so as to achieve the effect of clamping and positioning the COS chip through the two groups of clamping blocks 8, avoiding the deviation during polishing and grinding, and driving the lifting plate 1202 to descend through the telescopic end of the electric push rod 1201 until the polishing device body 1203 contacts the COS chip, and the polishing device body 1203 is started to position the COS chip. The S chip is polished and ground, and the P-side electrode of the COS chip is removed until the epitaxial layer of the COS chip is exposed. After the surface of the COS chip is polished and cleaned, the ball screw 401 is driven to rotate by the output shaft of the driving motor 402, thereby driving the driving block 403 to reciprocate along the axial direction of the ball screw 401, so as to move the COS chip after the polishing process to the bottom of the metallographic microscope 10, and the surface of the epitaxial layer of the COS chip is observed by the metallographic microscope 10 to preliminarily confirm the position of the abnormal point, and then the SEM electron microscope is used to perform energy spectrum analysis on the abnormal point to further verify whether the defect point on the epitaxial layer is true.

[0033] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A COS chip epitaxial surface defect failure analysis tool, characterized in that: include: A positioning substrate (1) and a stage (2), wherein a mounting shell (3) is fixedly mounted on the top of the positioning substrate (1), and a translation component (4) for adjusting the position of the stage (2) in a horizontal direction is arranged inside the mounting shell (3). A cavity (5) is arranged inside the loading platform (2), and two groups of through grooves (6) are symmetrically opened on the top of the loading platform (2), and connecting blocks (7) are slidably connected inside the two groups of through grooves (6), and clamping blocks (8) are fixedly connected to the tops of the two groups of connecting blocks (7); An adjustment component (9) disposed inside the cavity (5) and used for adjusting the distance between the two groups of clamping blocks (8); A metallographic microscope (10) is fixedly mounted on one side of the upper surface of the positioning substrate (1); a mold frame (11) is fixedly mounted on the top of the positioning substrate (1); and a polishing component (12) for polishing a COS chip is arranged on the top of the mold frame (11).

2. The COS chip epitaxial surface defect failure analysis tool according to claim 1, characterized in that: The translation assembly (4) comprises a ball screw (401), the two ends of the ball screw (401) are rotatably mounted on the inner walls of the mounting shell (3) on both sides respectively, one end of the ball screw (401) passes through the mounting shell (3) and is connected to a driving motor (402), a driving block (403) is threadedly connected on the outer wall of the ball screw (401), a T-block (404) is fixedly mounted on the top of the driving block (403), and the stage (2) is fixedly mounted on the top of the T-block (404).

3. The COS chip epitaxial surface defect failure analysis tool according to claim 2, characterized in that: The driving block (403) is located on both sides of the ball screw (401) and is slidably connected with guide rods (13), and the two ends of the two groups of guide rods (13) are respectively fixedly connected to the inner walls of the mounting shell (3).

4. The COS chip epitaxial surface defect failure analysis tool according to claim 3, characterized in that: The driving motor (402) is fixedly mounted on a side wall of the mounting shell (3), and one end of the output shaft of the driving motor (402) is fixedly connected to one end of the ball screw (401).

5. The COS chip epitaxial surface defect failure analysis tool according to claim 1, characterized in that: The adjustment assembly (9) comprises a worm (901), one end of which is rotatably mounted on an inner wall of one side of the cavity (5), one end of which passes through the stage (2) and is fixedly connected to a hand wheel (902), the top of the worm (901) is meshed with a worm wheel (903), a bidirectional lead screw (904) is fixedly inserted into the interior of the worm wheel (903), two groups of adjustment blocks (905) are symmetrically threadedly connected on the outer wall of the bidirectional lead screw (904), and the two groups of connection blocks (7) are respectively fixedly connected to the tops of the two groups of adjustment blocks (905).

6. The COS chip epitaxial surface defect failure analysis tool according to claim 5, characterized in that: The inner top of the cavity (5) is fixedly connected to a rotating seat (14), one end of the worm (901) is rotatably mounted on a side wall of the rotating seat (14), and the two ends of the bidirectional screw (904) are respectively rotatably mounted on the inner walls of both sides of the cavity (5).

7. The COS chip epitaxial surface defect failure analysis tool according to claim 1, characterized in that: The polishing assembly (12) comprises an electric push rod (1201), which is fixedly installed on the top of the mold frame (11), and one end of the telescopic end of the electric push rod (1201) passes through the mold frame (11) and is fixedly connected to a lifting plate (1202), and the bottom of the lifting plate (1202) is fixedly connected to a polishing device body (1203).

8. The COS chip epitaxial surface defect failure analysis tool according to claim 1, characterized in that: Four groups of L-shaped limiting members (15) are fixedly mounted on the top of the mounting shell (3), and the four groups of L-shaped limiting members (15) are symmetrically arranged in pairs.

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