Quartz diffusion furnace for semiconductor silicon wafer

Abstract

The invention belongs to the technical field of silicon wafer diffusion, and discloses a quartz diffusion furnace for semiconductor silicon wafers. The air chamber is arranged above the inner cavity of the furnace body and comprises a plurality of air outlets which are uniformly distributed and a plurality of air outlet pipes which are in sliding connection with the air chamber; the anti-collision mechanism is arranged in the air chamber and comprises round rods symmetrically arranged on the outer wall of the air outlet pipe and extrusion blocks abutting against the outer walls of the round rods; the adjusting mechanism is arranged in the furnace body and comprises a supporting plate, a third double-wedge rod linked with the supporting plate through an inclined surface, a second double-wedge rod meshed with the third double-wedge rod, and a first double-wedge rod linked with the second double-wedge rod and capable of horizontally moving; a limiting block is fixedly installed at the tail end of the round rod, and the tail end of the first double-wedge rod extends to the position below the limiting block. When a semiconductor silicon wafer is placed on the supporting plate, the extrusion assembly extrudes the limiting block according to the weight of the silicon wafer to enable the air outlet pipe to be at different heights. According to the invention, the problem that the diffusion uniformity and the yield are influenced after the size of the silicon wafer is adjusted by the existing equipment is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of silicon wafer diffusion, and specifically to a quartz diffusion furnace for semiconductor silicon wafers. Background Art

[0002] The diffusion furnace is one of the important process equipment in the front process of the semiconductor production line, and is used for processes such as diffusion, oxidation, annealing, alloying, and sintering in industries such as large-scale integrated circuits, discrete devices, power electronics, optoelectronic devices, and optical fibers.

[0003] Chinese Patent Publication No. 202123005186.4, "Vertical Diffusion Furnace with Uniform Diffusion of Reaction Gas", includes a vertical diffusion furnace body and a wafer body. A shunt box is provided on the left side of the vertical diffusion furnace body. The inlet of the shunt box is connected to an inlet pipe, and an air pump is provided on the inlet pipe. A guiding block is provided on the right side of the inner cavity of the shunt box. Air holes are opened at both the upper and lower ends of the shunt box. The two air holes are connected to the upper and lower ends of the inner cavity of the vertical diffusion furnace body through a connecting pipe. The bottom ends of the two connecting pipes are connected to a connecting pipe, and the bottom ends of the two connecting pipes are provided with an inner furnace pipe. A plurality of air outlet holes are opened on one side of the inner furnace pipe. The outlet of the vertical diffusion furnace body is connected to an outlet pipe.

[0004] The existing diffusion furnace outlet is usually designed according to the current semiconductor silicon wafer size. The distance between the outlet and the semiconductor silicon wafer is appropriate, and the gas can act on the surface of the semiconductor silicon wafer evenly, and a certain flow field distribution is formed in the furnace to achieve a uniform diffusion effect.

[0005] However, with the development of the diversification of semiconductor silicon wafer sizes (such as the transition from 8 inches to 12 inches), when the silicon wafer size changes, the original balance is broken, which will affect the diffusion uniformity and the yield rate. Summary of the Invention

[0006] The purpose of the present invention is to provide a quartz diffusion furnace for semiconductor silicon wafers, and the present invention solves the problem that the existing equipment affects the diffusion uniformity and the yield rate after the silicon wafer size is adjusted.

[0007] To achieve the above object, the present invention provides the following technical solution: A quartz diffusion furnace for semiconductor silicon wafers, comprising: A furnace body; An air chamber, arranged above the inner cavity of the furnace body, including a plurality of uniformly distributed air outlet holes and a plurality of air outlet pipes slidably connected to the air chamber; An anti-collision mechanism, arranged inside the air chamber, including round rods symmetrically arranged on the outer wall of the air outlet pipe, and extrusion blocks abutted against the outer wall of the round rods; The adjusting mechanism is arranged inside the furnace body and includes a support plate, a third double wedge rod linked with the support plate through an inclined surface, a second double wedge rod meshed with the third double wedge rod, and a first double wedge rod linked with the second double wedge rod and capable of horizontal movement; A limiting block is fixedly installed at the end of the round rod, and the end of the first double wedge rod extends below the limiting block; when the semiconductor silicon wafer is placed on the support plate, the extrusion assembly presses the limiting block according to the weight of the silicon wafer, causing the air outlet pipe to be at different heights.

[0008] Preferably, a furnace door is slidably installed on the outer wall of the furnace body, and a capacitance sensor is installed on the outer wall of the furnace body.

[0009] Preferably, an air inlet pipe is installed on the upper end face of the furnace body, and the air inlet pipe is communicated with the air chamber.

[0010] Preferably, a groove adapted to the support plate is opened inside the furnace body, and a plurality of first springs are uniformly installed on the outer wall of the groove, and the first springs are fixedly connected with the support plate.

[0011] Preferably, a hydraulic rod is fixedly installed on the outer wall of the furnace body, the output shaft of the hydraulic rod penetrates through the furnace body and is fixedly installed with a sliding plate, and sliding rods are symmetrically installed on one side of the sliding plate away from the hydraulic rod, and the sliding rods are fixedly connected with the extrusion block.

[0012] Preferably, a second spring is installed on the upper end face of the limiting block, and the side of the second spring away from the limiting block is installed on the furnace body.

[0013] Preferably, the inclined surfaces are symmetrically opened on the support plate.

[0014] Preferably, the third double wedge rod, the second double wedge rod and the first double wedge rod are all slidably connected with the furnace body.

[0015] Preferably, the limiting block is slidably connected with the furnace body.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: First, the present invention is provided with an adjusting mechanism. When the size of the semiconductor silicon wafer changes, the weight will also change accordingly. The support plate will press the first spring, causing it to deform, and the inclined surface of the support plate will start to press the third double wedge rod to move horizontally. The third double wedge rod presses the first double wedge rod to move horizontally through the second double wedge rod; If the outer size of the semiconductor silicon wafer becomes larger, the weight will also be heavier. At this time, the first double wedge rod extends more, and the descending space of the limiting block is smaller, so that the length of the air outlet pipe extending out of the air chamber becomes shorter; if the outer size of the semiconductor silicon wafer becomes smaller, the weight will also be lighter. At this time, the first double wedge rod extends less, and the descending space of the limiting block is larger, so that the length of the air outlet pipe extending out of the air chamber becomes longer. It can always keep an appropriate distance between the air outlet pipe and the semiconductor silicon wafer, ensure that the gas acts uniformly on the surface of the semiconductor silicon wafer, and improve the diffusion uniformity and the yield rate.

[0017] Second, the present invention is provided with an anti-collision mechanism. When the hydraulic rod extends, it pushes the sliding plate to move in the air chamber. The sliding plate drives the sliding rod to move, the sliding rod drives the extrusion block to move, the extrusion block will extrude the round rod, and the round rod drives the limiting block and the air outlet pipe to move upward. At this time, the limiting block extrudes the second spring, and the air outlet pipe retracts into the air chamber to prevent the quartz boat from colliding with the air outlet pipe when it is put in, causing damage. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is a schematic diagram of the overall structure of the present invention; Figure 2 is Figure 1 a schematic diagram of another perspective; Figure 3 is a sectional view of the present invention; Figure 4 is a schematic diagram of the internal structure of the furnace body of the present invention; Figure 5 is Figure 4 an enlarged schematic diagram of part A in Figure 6 is Figure 4 a schematic diagram of another perspective; Figure 7 is a schematic diagram of the third double wedge rod, the second double wedge rod and the first double wedge rod of the present invention.

[0019] In the figure: 1. Furnace body; 2. Hydraulic rod; 3. Inlet pipe; 4. Furnace door; 5. Capacitive sensor; 6. Air chamber; 7. Sliding plate; 8. Air outlet pipe; 9. Air outlet; 10. Support plate; 11. First spring; 12. First double wedge rod; 13. Second double wedge rod; 14. Sliding rod; 15. Extrusion block; 16. Round rod; 17. Second spring; 18. Limiting block; 19. Third double wedge rod; 20. Inclined surface. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0020] To more clearly understand the purpose, technical solution and advantages of the present application, the present application will be described and illustrated below with reference to the drawings and embodiments.

[0021] Please refer to Figures 1 to 7 , the present invention provides a technical solution: a quartz diffusion furnace for semiconductor silicon wafers, including: Furnace body 1; Air chamber 6, arranged above the inner cavity of the furnace body 1, including a plurality of uniformly distributed air outlets 9 and a plurality of air outlet pipes 8 slidably connected to the air chamber 6; Anti-collision mechanism, arranged inside the air chamber 6, including round rods 16 symmetrically arranged on the outer wall of the air outlet pipe 8 and extrusion blocks 15 abutting against the outer wall of the round rods 16; The adjusting mechanism is arranged inside the furnace body 1 and includes a support plate 10, a third double-wedge rod 19 linked with the support plate 10 through an inclined surface 20, a second double-wedge rod 13 meshed with the third double-wedge rod 19, and a first double-wedge rod 12 linked with the second double-wedge rod 13 and capable of horizontal movement; A limit block 18 is fixedly installed at the end of the round rod 16, and the end of the first double-wedge rod 12 extends below the limit block 18; when a semiconductor silicon wafer is placed on the support plate 10, the extrusion assembly extrudes the limit block 18 according to the weight of the silicon wafer, so that the air outlet pipe 8 is at different heights.

[0022] Further, as Figure 2 shown, a furnace door 4 is slidably installed on the outer wall of the furnace body 1, and a capacitance sensor 5 is installed on the outer wall of the furnace body 1; In this embodiment, a pushing device is installed above the furnace door 4 and is a prior art. Its working principle is to realize the opening and closing actions of the furnace door 4 through [brief principle, such as hydraulic drive, electric drive, etc.] to meet the requirements for opening and closing the furnace door 4 during the operation of the diffusion furnace.

[0023] Further, as Figure 2 shown, an air inlet pipe 3 is installed on the upper end surface of the furnace body 1. The air inlet pipe 3 is communicated with an air chamber 6, and an electromagnetic valve (not shown in the figure) is installed in the air inlet pipe 3; The outside of the air inlet pipe 3 is communicated with a gas source device. After the electromagnetic valve is opened, gas enters the air chamber 6 from both sides, so that the reaction gas output is uniform.

[0024] Further, as Figure 3 and Figure 7 shown, a groove adapted to the support plate 10 is formed inside the furnace body 1, and a plurality of first springs 11 are uniformly installed on the outer wall of the groove. The first springs 11 are fixedly connected with the support plate 10; The first springs 11 are used for the support plate 10 to reset. After the support plate 10 is reset, the second double-wedge rod 13 descends, extruding the third double-wedge rod 19 back to the initial position, and the limit block 18 will extrude the first double-wedge rod 12 back to the initial position.

[0025] Further, as Figure 3 and Figure 5 shown, a hydraulic rod 2 is fixedly installed on the outer wall of the furnace body 1. The output shaft of the hydraulic rod 2 penetrates through the furnace body 1 and is fixedly installed with a slide plate 7. Two slide rods 14 are symmetrically installed on one side of the slide plate 7 away from the hydraulic rod 2, and the slide rods 14 are fixedly connected with an extrusion block 15; a second spring 17 is installed on the upper end surface of the limit block 18, and one side of the second spring 17 away from the limit block 18 is installed on the furnace body 1; When the hydraulic rod 2 works, it drives the slide plate 7 to move. The slide plate 7 drives the slide rod 14 to move, and the slide rod 14 drives the extrusion block 15 to move. The extrusion block 15 squeezes or moves away from the round rod 16. At this time, the second spring 17 makes the round rod 16 and the extrusion block 15 always in contact through the limit block 18.

[0026] Further, as Figure 6 shown, the inclined surfaces 20 are symmetrically formed on the support plate 10 to squeeze the third double wedge rod 19.

[0027] Further, as Figure 7 shown, the third double wedge rod 19, the second double wedge rod 13 and the first double wedge rod 12 are all slidably connected to the furnace body 1, and the limit block 18 is slidably connected to the furnace body 1; When the third double wedge rod 19 is squeezed, it moves horizontally and simultaneously squeezes the second double wedge rod 13. The second double wedge rod 13 moves vertically and squeezes the first double wedge rod 12 to make it move horizontally. At this time, the end of the first double wedge rod 12 is below the limit block 18 and will block the downward movement of the limit block 18.

[0028] Working principle: Step 1: After connecting the external power supply and the controller, first open the furnace door 4. At this time, the furnace door 4 is away from the capacitance sensor 5. After the capacitance sensor 5 feeds back to the controller, the hydraulic rod 2 extends, pushing the slide plate 7 to move in the air chamber 6. The slide plate 7 drives the slide rod 14 to move, and the slide rod 14 drives the extrusion block 15 to move. The extrusion block 15 will squeeze the round rod 16, and the round rod 16 drives the limit block 18 and the air outlet pipe 8 to move upward. At this time, the limit block 18 squeezes the second spring 17, and the air outlet pipe 8 retracts into the air chamber 6 to prevent the air outlet pipe 8 from being damaged when the quartz boat is placed and collides with the air outlet pipe 8.

[0029] Step 2: Place the quartz boat containing the semiconductor silicon wafer on the support plate 10. The support plate 10 compresses the first spring 11, and the inclined surface 20 of the support plate 10 will squeeze the third double wedge rod 19. The third double wedge rod 19 squeezes the second double wedge rod 13, and the second double wedge rod 13 squeezes the first double wedge rod 12. At this time, the first double wedge rod 12 extends below the limit block 18.

[0030] Step 3: After the quartz boat is placed, close the furnace door 4 at this time. When the furnace door 4 contacts the capacitance sensor 5, the capacitance sensor 5 feeds back to the controller. At this time, the hydraulic rod 2 contracts, driving the slide plate 7 to contract in the air chamber 6. The slide plate 7 drives the slide rod 14 to move, and the slide rod 14 drives the extrusion block 15 to move. The extrusion block 15 no longer presses the round rod 16. At this time, the second spring 17 extends, driving the limit block 18 and the air outlet pipe 8 to move downward. When the limit block 18 contacts the first double-wedge rod 12, it stops. Subsequently, the furnace body 1 starts to heat up. When it is necessary to introduce the required reaction gas, connect an external gas source through the inlet pipe 3, and introduce the gas into the air chamber 6. The gas is discharged into the furnace body 1 through the air outlet pipe 8 and the air outlet 9. Since the air outlet pipe 8 and the air outlet 9 are arranged in a rectangular pattern above the furnace body 1, the gas will be evenly diffused in the furnace body 1, and finally the processing is completed.

[0031] Step 4: When processing again, if the external dimensions of the semiconductor silicon wafer change at this time, the weight will change accordingly. The support plate 10 presses the first spring 11. At this time, the first spring 11 deforms differently, and the support plate 10 presses the third double-wedge rod 19 to move a certain distance through the inclined surface 20. The third double-wedge rod 19 presses the first double-wedge rod 12 to move a certain distance through the second double-wedge rod 13, so that the end of the first double-wedge rod 12 extends below the limit block 18. When the limit block 18 descends and abuts against the first double-wedge rod 12, the round rod 16 drives the air outlet pipe 8 to extend a certain distance. At this time, an appropriate distance is maintained between the air outlet pipe 8 and the semiconductor silicon wafer, so that the gas acts evenly on the surface of the semiconductor silicon wafer, improving the diffusion uniformity and the yield rate.

[0032] In this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprising", "including" or any other variant thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "comprising an..." does not exclude the existence of additional identical elements in the process, method, article or device comprising the element.

[0033] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A quartz diffusion furnace for semiconductor silicon wafers, characterized in that, Including: Furnace body (1); Gas chamber (6), arranged above the inner cavity of the furnace body (1), including a plurality of uniformly distributed air outlets (9) and a plurality of air outlet pipes (8) slidably connected to the gas chamber (6); Anti-collision mechanism, arranged inside the gas chamber (6), including round rods (16) symmetrically arranged on the outer wall of the air outlet pipe (8), and extrusion blocks (15) abutting against the outer wall of the round rods (16); Adjusting mechanism, arranged inside the furnace body (1), including a support plate (10), a third double-wedge rod (19) linked with the support plate (10) through an inclined surface (20), a second double-wedge rod (13) engaged with the third double-wedge rod (19), and a first double-wedge rod (12) linked with the second double-wedge rod (13) and capable of horizontal movement; A limit block (18) is fixedly installed at the end of the round rod (16), and the end of the first double-wedge rod (12) extends below the limit block (18); when a semiconductor silicon wafer is placed on the support plate (10), the extrusion assembly presses the limit block (18) according to the weight of the silicon wafer to make the air outlet pipe (8) at different heights.

2. The quartz diffusion furnace for semiconductor silicon wafers according to claim 1, wherein: A furnace door (4) is slidably installed on the outer wall of the furnace body (1), and a capacitance sensor (5) is installed on the outer wall of the furnace body (1).

3. The quartz diffusion furnace for semiconductor silicon wafers according to claim 1, characterized in that: An air inlet pipe (3) is installed on the upper end surface of the furnace body (1), and the air inlet pipe (3) is communicated with the gas chamber (6).

4. A quartz diffusion furnace for semiconductor silicon wafers according to claim 1, characterized in that: A groove adapted to the support plate (10) is opened inside the furnace body (1), and a plurality of first springs (11) are uniformly installed on the outer wall of the groove, and the first springs (11) are fixedly connected with the support plate (10).

5. A quartz diffusion furnace for a semiconductor silicon wafer according to claim 1, characterized in that: A hydraulic rod (2) is fixedly installed on the outer wall of the furnace body (1), the output shaft of the hydraulic rod (2) penetrates the furnace body (1) and is fixedly installed with a sliding plate (7), and sliding rods (14) are symmetrically installed on one side of the sliding plate (7) away from the hydraulic rod (2), and the sliding rods (14) are fixedly connected with the extrusion blocks (15).

6. The quartz diffusion furnace for semiconductor silicon wafers according to claim 1, characterized in that: A second spring (17) is installed on the upper end surface of the limit block (18), and one side of the second spring (17) away from the limit block (18) is installed on the furnace body (1).

7. A quartz diffusion furnace for semiconductor silicon wafers according to claim 1, characterized in that: The inclined surfaces (20) are symmetrically opened on the support plate (10).

8. A quartz diffusion furnace for semiconductor silicon wafers according to claim 1, characterized in that: The third double-wedge rod (19), the second double-wedge rod (13) and the first double-wedge rod (12) are all slidably connected with the furnace body (1).

9. The quartz diffusion furnace for a semiconductor silicon wafer according to claim 8, characterized in that: The limit block (18) is slidably connected with the furnace body (1).

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