Semiconductor manufacturing equipment and method for manufacturing a semiconductor device

Abstract

Semiconductor manufacturing equipment (100, 200, 300), comprising: a table (2) having a mounting area (2a) for a wafer (1) on an upper surface; a plurality of intake tubes (4) extending from the mounting area (2a) through the table (2) to one side of the rear surface of the table (2); a vacuum pump (3) which is connected to the plurality of intake tubes (4) and draws the wafer (1) to the assembly area (2a) via the plurality of intake tubes (4); a tray (6) which is arranged on the upper surface of the table (2) and covers the wafer (1); a gas supply line (7) that pressurizes a space surrounded by the upper surface of the table (2) and the bowl (6); and a pressure sensor (5) that detects pressure in the plurality of intake pipes (4).

Description

Background of the invention: Area

[0001] The present disclosure relates to a semiconductor manufacturing device and a method for manufacturing a semiconductor device. background

[0002] JP 2013 - 149 809 A discloses a method for detecting foreign bodies in a suction table. The suction table comprises: a placement area onto which a substrate is suctioned and fixed; a pressure measuring device for measuring the suction pressure of the substrate in the placement area; and a determination unit that determines the presence or absence of a suction anomaly of the substrate. The foreign body detection method comprises a measurement step and a determination step. In the measurement step, the pressure measuring device measures the suction pressure of the substrate on the placement surface. In the determination step, the determination unit determines fluctuation data and compares it with reference fluctuation data. The fluctuation data, among the suction pressure data acquired in the measurement step, are data from the beginning of the substrate's suction until the time before the numerical value of the suction pressure stabilizes.The reference fluctuation data are data generated when no foreign object is present on the placement surface and are stored in the detection unit beforehand. In this way, the detection unit determines the presence or absence of a suction anomaly on the placement surface, in order to determine the presence or absence of a foreign object on the placement surface.

[0003] The foreign body detection method described in JP 2013-149809A is a technique for detecting a foreign body on the table. Therefore, it is possible that a defect in a table-mounted semiconductor wafer may not be detected because the fluctuation in suction pressure caused by the defect is excessively small. Summary

[0004] It is an object of the present invention to provide a semiconductor manufacturing device and a method for manufacturing a semiconductor device that can detect a defect in a wafer.

[0005] The features and advantages of the present disclosure can be summarized as follows.

[0006] According to one aspect of the present disclosure, a semiconductor manufacturing apparatus comprises a table having a mounting area for a wafer on an upper surface, a plurality of intake tubes extending from the mounting area through the table to one side of the rear surface of the table, a vacuum pump connected to the plurality of intake tubes and drawing the wafer to the mounting area via the plurality of intake tubes, a tray arranged on the upper surface of the table and covering the wafer, a gas supply line that pressurizes a space surrounded by the upper surface of the table and the tray, and a pressure sensor that detects a pressure in the plurality of intake tubes.

[0007] According to one aspect of the present disclosure, a method for manufacturing a semiconductor device comprises mounting a wafer in a mounting area arranged on the upper surface of a table, mounting a tray on the upper surface of the table to cover the wafer, supplying gas to a space surrounded by the upper surface of the table and the tray to pressurize the wafer, drawing the wafer to the mounting area by a vacuum pump connected to a plurality of suction tubes extending from the mounting area through the table to one side of the rear surface of the table, detecting the pressure in the plurality of suction tubes while the wafer is being pressurized and drawn to the mounting area, and performing a cleaning, film formation, photolithography, or etching process.a diffusion treatment or ion implantation on the wafer, after the pressure in the multitude of intake tubes has been detected.

[0008] Other and further tasks, features and benefits of the revelation will become more apparent from the following detailed description. Brief description of the drawings Fig. Figure 1 is a top view and a front view of a semiconductor manufacturing facility according to a first embodiment. Fig. Figure 2 is a top view and a front view illustrating a state in which a shell is attached to the semiconductor manufacturing equipment according to the first embodiment. Fig. Figure 3 is a top view and a front view of a semiconductor manufacturing facility according to a modification of the first embodiment. Fig. Figure 4 shows a top view and a front view of a semiconductor manufacturing facility according to a second embodiment. Fig. Figure 5 is a view to explain a method for inspecting a semiconductor device according to the second embodiment. Fig. Figure 6 is a flowchart to explain a method for manufacturing a semiconductor device according to a third embodiment. Description of embodiments

[0009] Semiconductor manufacturing equipment and methods for manufacturing semiconductor devices according to embodiments of the present disclosure are described with reference to the accompanying drawings. Components that are identical or equivalent to one another are indicated by the same reference numerals, and their repeated description is omitted in some cases. First embodiment.

[0010] Fig. Figure 1 shows a top view and a front view of a semiconductor manufacturing device 100 according to a first embodiment. The semiconductor manufacturing device 100 has a table 2 on its upper surface with a mounting area 2a for a wafer 1. The wafer 1 is a semiconductor substrate. The semiconductor manufacturing device 100 has a plurality of suction lines or suction tubes 4 extending from the mounting area 2a through the table 2 to the side of the rear surface of the table 2. Each suction tube 4 has a first subsection 4a located inside the table 2 and a second subsection 4b extending from the rear surface of the table 2 and located outside the table 2. The vacuum pump 3 is connected to the plurality of suction tubes 4 and draws the wafer 1 through the plurality of suction tubes 4 to the mounting area 2a. Each suction tube 4 is provided with a pressure sensor 5.The pressure sensor 5 detects the pressure in the intake pipe 4.

[0011] Table 2 is virtually divided into a grid shape to form a multitude of suction surfaces 2b. Each of the multitude of suction surfaces 2b is equipped with the suction pipe 4. In Fig. The positions of the intake openings 4c of the plurality of intake tubes 4 are indicated by dashed lines. The intake openings 4c are arranged in a grid pattern in the assembly area 2a. The vacuum pump 3 draws the wafer 1 to each intake surface 2b using negative pressure or a vacuum.

[0012] The pressure sensor 5, connected to the intake tube 4, monitors the pressure for each intake surface 2b. When the wafer 1 with a defect 1a, such as a through-hole, is drawn in, the pressure at the intake surface 2b with the defect 1a will differ from the pressure at the intake surface 2b without a defect 1a. In this way, pressure fluctuations can be detected by the pressure sensor 5 to identify a defect.

[0013] The size of the sampling area 2b is determined according to the size of the defect 1a to be detected. For example, if a wafer diameter is 20.32 cm (8 inches) and a defect of approximately 10 µm to 1 cm² is to be detected, the sampling area can be as small as 1 cm². In this case, the number of sampling areas 2b is approximately 20 per row. Accordingly, it is sufficient to provide approximately 400 pressure sensors 5. The number of pressure sensors 5 per row or in total can be changed according to the diameter of the wafer 1. For example, if the diameter of the wafer 1 is 10.16 cm (4 inches) to 30.48 cm (12 inches) and the sampling area 2b is 1 cm², it is sufficient to provide approximately 10 to 30 pressure sensors 5 per row, thus a total of approximately 100 to 900 pressure sensors 5.

[0014] Fig. Figure 2 shows a top and front view illustrating a state in which a tray 6 is attached to the semiconductor manufacturing device 100 according to the first embodiment. The semiconductor manufacturing device 100 has the tray 6, which is arranged on the upper surface of the table 2 and covers the wafer 1. The tray 6 has a box or dome shape. The tray 6 is in tight contact with the table 2 to ensure an airtight seal inside. The tray 6 is connected to a gas supply line 7. The gas supply line 7 pressurizes the space surrounded by the upper surface of the table 2 and the tray 6. The gas supply line 7 supplies, for example, N2 into the tray 6.

[0015] The gas enclosed in tray 6 presses the entire surface of wafer 1 against the table 2. Thus, due to the defect on the surface of wafer 1, a pressure fluctuation occurs in the intake tube 4. If the defect is a through-hole, the gas supplied by gas supply line 7 escapes through the defect into the intake tube 4. Consequently, a pressure fluctuation occurs in the intake tube 4. Therefore, the detection sensitivity for defects can be improved, and a defect in wafer 1, such as a through-hole, can be detected. In the present embodiment, even a tiny defect, for example, from 10 µm to 1 cm, can be detected. Examples of defects that should be detected in the present embodiment include a through-hole such as a microtube, a crack that reaches the back surface of wafer 1 from its front surface, and the like.

[0016] Wafer 1 is made of silicon. Alternatively, wafer 1 can be made of a wide-bandgap semiconductor with a bandgap larger than that of silicon. Examples of wide-bandgap semiconductors include silicon carbide, gallium nitride-based materials, and diamond. Silicon carbide, in particular, exhibits many crystal polymorphisms, and it is difficult to form a SiC crystal with only one crystal polymorphism. Compared to silicon, silicon carbide tends to introduce defects due to the incorporation of other crystal polymorphisms during crystal growth. Therefore, a through-hole, such as a microtube, tends to form. For this reason, the present embodiment is especially effective when wafer 1 is made of a wide-bandgap semiconductor.

[0017] Furthermore, silicon or silicon carbide is a transparent material. For this reason, light passes through wafer 1, making it difficult to detect the defect using light. In contrast, in the present embodiment, since the defect is detected by means of pressure fluctuations, it is possible to detect the defect itself within wafer 1, through which light passes. The microtube is generally inclined. Thus, it is difficult to detect the microtube with light. In contrast, in the present embodiment, the defect is detected by subdividing the suction surface 2b and drawing the wafer 1 against each suction surface 2b with a vacuum. Therefore, it is possible to improve the detection sensitivity of the microtube.

[0018] Fig. Figure 3 shows a top view and a front view of a semiconductor manufacturing apparatus 200 according to a modification of the first embodiment. In addition to N₂, helium can be supplied to the gas supplied through the gas supply line 7. The semiconductor manufacturing apparatus 200 can also include a densitometer 205, which detects the concentration of the helium gas supplied through the gas supply line 7, in each of the plurality of intake tubes 4. The densitometer 205 is arranged in each intake tube 4.

[0019] In the semiconductor manufacturing device 200, the helium gas escapes through the defect into the intake tube 4, thus changing the concentration of helium gas in the intake tube 4. By using the pressure sensor 5 and the densitometer 205 together in this way, it is possible to detect even a minute defect that passes through the wafer 1. Furthermore, the helium gas is easy to handle, as it is a gas commonly used for leak detection. Although the example described here uses the pressure sensor 5 and the densitometer 205 together, the densitometer 205 can also be used alone.

[0020] These modifications can be suitably used for semiconductor manufacturing equipment and methods for manufacturing semiconductor devices according to the embodiments below. However, for the semiconductor manufacturing equipment and methods for manufacturing the semiconductor devices according to the embodiments below, primarily differences from the first embodiment are explained, since they exhibit many similarities to the first embodiment. Second embodiment.

[0021] Fig. Figure 4 shows a top view and a front view of a semiconductor manufacturing device 300 according to a second embodiment. The semiconductor manufacturing device 300 has a pressure sensor 5. The semiconductor manufacturing device 300 has a plurality of valves 308, each arranged between a plurality of intake tubes 4 and a pressure sensor 5. Each intake surface 2b and the pressure sensor 5 are connected via the valve 308.

[0022] The semiconductor manufacturing device 300 further comprises a detector 309 which, based on the pressure measured by the pressure sensor 5, detects the presence or absence of a defect in a region of the wafer 1 that each of the plurality of intake tubes 4 draws in. The detector 309 sequentially opens the plurality of valves 308 and, based on the pressure in the intake tube 4 corresponding to each of the valves 308 in the open state, detects the presence or absence of a defect in a region of the wafer 1 that the intake tube 4 draws in.

[0023] The detector 309 includes, for example, an opening / closing unit 309a, a measuring unit 309b, a determination unit 309c, and an output unit 309d. The opening / closing unit 309 controls the opening and closing of the valves 308 and sequentially switches the multiple valves 308 to the open state. The measuring unit 309 measures the pressure in the intake pipe 4, which corresponds to the valve 308 in the open state. The determination unit 309c determines the presence or absence of a defect based on the pressure measured by the measuring unit 309b. The output unit 309d outputs the determination result from the determination unit 309c.

[0024] In the suction area 2b, which corresponds to valve 308 in a closed state, the wafer 1 is drawn in by vacuum. In the suction area 2b, which corresponds to valve 308 in an open state, the presence or absence of a defect in wafer 1 is determined. This enables inspection using a pressure sensor 5. Therefore, space savings and cost reductions can be achieved.

[0025] Similarly, the semiconductor manufacturing device 300 can include a densitometer 205, and each intake surface 2b and the densitometer 205 can be connected via the valve 308. In this case, the detector 309 detects the presence or absence of a defect in a region of the wafer 1 that each of the plurality of intake tubes 4 draws in, based on the gas concentration measured by the densitometer 205. The detector 309 sequentially opens the plurality of valves 308 and detects, based on the gas concentration in the intake tube 4 corresponding to each of the valves 308 in the open state, the presence or absence of a defect in a region of the wafer 1 that the intake tube 4 draws in. At this time, the measuring unit 309b measures the gas concentration in the intake tube 4 corresponding to the valve 308 in the open state.The determination unit 309c determines the presence or absence of a defect based on the concentration measured by the measuring unit 309b.

[0026] Fig. Figure 5 is a view to illustrate a method for inspecting a semiconductor device according to the second embodiment. As indicated by arrow 81 in Fig. As specified in 5, the defect can be detected sequentially from the peripheral region of wafer 1 towards its center. That is, detector 309 can detect the presence or absence of a defect in the center of wafer 1 after the presence or absence of a defect in the peripheral region of wafer 1 has been detected. In the Fig. In the illustrated example 5, the inspection is performed sequentially in the circumferential direction of wafer 1. Generally, defects tend to occur in the peripheral region of wafer 1. This is because contact with a cassette for storing wafer 1 or a device for mounting wafer 1 applies physical stress to the peripheral region. By performing the inspection from the peripheral region, the inspection time can therefore be reduced and productivity improved.

[0027] The detector 309 of the present embodiment can be arranged in the semiconductor manufacturing device 100 or the semiconductor manufacturing device 200 of the first embodiment. In this case, the opening / closing unit 309a does not need to be arranged. Third embodiment.

[0028] Fig. Figure 6 is a flowchart to explain a method for manufacturing a semiconductor device according to a third embodiment. Fig. Figure 6 illustrates a method for fabricating a semiconductor device using the semiconductor fabrication equipment according to the first or second embodiment. First, a preparation step (S1) is performed to prepare the wafer 1. In this preparation step, an ingot of, for example, silicon or silicon carbide is sliced ​​into wafers of a predetermined thickness to prepare the wafer 1. Epitaxial growth can then be performed on the sliced ​​substrate in step S1 to prepare the wafer 1.

[0029] In step S2, wafer 1 is next introduced into a product manufacturing process. This process for manufacturing a semiconductor device comprises a cleaning step (shown in step S3), a film formation step (shown in step S4), a photolithography step (shown in step S5), an etching step (shown in step S6), and a diffusion and ion implantation step (shown in step S7). A generally known manufacturing process can be used for these steps. The film formation step includes oxidation, chemical vapor deposition (CVD), metallization, and the like.

[0030] In the inspection step using the semiconductor manufacturing device 100, wafer 1 is mounted on the assembly area 2a located on the upper surface of the table 2. Next, the tray 6 is mounted on the upper surface of the table 2 to cover wafer 1. Gas is then introduced into the space enclosed by the upper surface of the table 2 and the tray 6 to pressurize wafer 1. The vacuum pump 3 draws wafer 1 into the assembly area 2a. The pressure in each of the multiple intake tubes 4 is detected while wafer 1 is pressurized with gas as it is drawn into the assembly area 2a. If semiconductor manufacturing device 200 or 300 is used, the gas concentration in each of the multiple intake tubes 4 is detected while wafer 1 is pressurized with gas as it is drawn into the assembly area 2a. This checks for the presence or absence of a defect in wafer 1.

[0031] The present embodiment comprises an inspection step performed by the semiconductor manufacturing equipment 100, 200, or 300 prior to at least one of the cleaning step, film formation step, photolithography step, etching step, and diffusion and ion implantation step. That is, after the pressure or gas concentration in each of the plurality of intake tubes 4 has been detected and the inspection performed, the wafer 1 is subjected to cleaning, film formation, photolithography, etching, diffusion treatment, or ion implantation. As a result, it is possible in the semiconductor device manufacturing process to prevent a secondary problem such as a stage abnormality, which can occur due to processing a defective wafer.

[0032] By performing the inspection step before each step, the following effects, for example, can be achieved. Performing the inspection step before the cleaning step or the photolithography step prevents corrosion of the print bed due to the influx of a chemical solution from the defect. Furthermore, it prevents contamination of the subsequent wafer. Performing the inspection step before the film formation step prevents a product obtained through film formation from passing through the defect and being deposited on the print bed. Performing the inspection step before the etching step prevents corrosion of the print bed due to the influx of etching gas from the defect. Furthermore, it prevents contamination of the subsequent wafer.By performing the inspection step before the diffusion and ion implantation step, it is possible to prevent the table from burning due to laser irradiation of the defect during laser healing or the like.

[0033] However, the technical features described in each embodiment can be combined in a suitable manner for use.

[0034] In the semiconductor manufacturing device and the method for manufacturing a semiconductor device according to the present disclosure, gas can be supplied to the space enclosed by the upper surface of the table and the tray in order to pressurize the wafer. Accordingly, a defect in the wafer can be detected.

Claims

[1] Semiconductor manufacturing equipment (100, 200, 300), comprising: a table (2) having a mounting area (2a) for a wafer (1) on an upper surface; a plurality of intake tubes (4) extending from the mounting area (2a) through the table (2) to one side of the rear surface of the table (2); a vacuum pump (3) which is connected to the plurality of intake tubes (4) and draws the wafer (1) to the assembly area (2a) via the plurality of intake tubes (4); a tray (6) which is arranged on the upper surface of the table (2) and covers the wafer (1); a gas supply line (7) that pressurizes a space surrounded by the upper surface of the table (2) and the bowl (6); and a pressure sensor (5) that detects pressure in the plurality of intake pipes (4). [2] Semiconductor manufacturing apparatus (100, 200, 300) according to claim 1, further comprising a detector (309) which detects the presence or absence of a defect in an area of ​​the wafer (1) which each of the plurality of intake tubes (4) draws in, based on the pressure measured by the pressure sensor (5). [3] Semiconductor manufacturing apparatus (100, 200, 300) according to claim 1 or 2, further comprising a densitometer (205) which detects a concentration of a gas supplied by the gas supply line (7) in the plurality of intake tubes (4). [4] Semiconductor manufacturing apparatus (100, 200, 300) according to any one of claims 1 to 3, wherein the pressure sensor (5) is arranged in each of the plurality of intake tubes (4). [5] Semiconductor manufacturing apparatus (100, 200, 300) according to claim 2, further comprising a plurality of valves (308) each arranged between the plurality of intake tubes (4) and the pressure sensor (5); wherein the detector (309) sequentially opens the plurality of valves (308) and detects the presence or absence of the defect in an area of ​​the wafer (1) which the intake tube corresponding to the valve (308) in the open state draws in, based on the pressure in the intake tube (4) corresponding to the valve (308) in the open state. [6] Semiconductor manufacturing apparatus (100, 200, 300) according to claim 5, wherein the detector (309) detects the presence or absence of the defect in a center of the wafer (1) after detecting the presence or absence of the defect in a peripheral subregion of the wafer (1). [7] Semiconductor manufacturing apparatus (100, 200, 300) according to any one of claims 1 to 6, wherein intake openings (4c) of the plurality of intake tubes (4) are arranged in a grid shape in the assembly area (2a). [8] Semiconductor manufacturing apparatus (100, 200, 300) according to any one of claims 1 to 7, wherein the gas supplied through the gas supply line (7) is He or N2. [9] Semiconductor manufacturing apparatus (100, 200, 300) according to any one of claims 1 to 8, wherein the wafer (1) is made from a wide bandgap semiconductor. [10] Semiconductor manufacturing apparatus (100, 200, 300) according to claim 9, wherein the wide bandgap semiconductor is silicon carbide, a gallium nitride-based material or diamond. [11] Method for manufacturing a semiconductor device, wherein the method comprises: mounting a wafer (1) in a mounting area (2a) which is arranged on an upper surface of a table (2); mounting a tray (6) on the upper surface of the table (2) to cover the wafer (1); supplying gas to a space surrounded by the upper surface of the table (2) and the tray (6) to pressurize the wafer (1): a suction of the wafer (1) to the assembly area (2a) by a vacuum pump (3) which is connected to a plurality of suction tubes (4) which extend from the assembly area (2a) through the table (2) to one side of the rear surface of the table (2); a detection of the pressure in the plurality of suction tubes (4) while the wafer (1) is pressurized and the wafer (1) is drawn to the assembly area (2a); and a cleaning, film formation, photolithography, etching, diffusion treatment or ion implantation on the wafer (1) after detecting the pressure in the plurality of suction tubes (4).

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