Wafer heater with highly adjustable cooling capacity

Abstract

The present invention discloses a wafer heater with greatly adjustable cooling capacity, comprising an upper plate, an armored heating tube embedded in the top surface of the inner hole of the upper plate, and a temperature measuring thermocouple arranged in the middle of the upper plate; a cover plate, a cooling plate and a support shaft are arranged in the inner hole of the upper plate from top to bottom in sequence; a shoulder A on the support shaft is clamped at the lower end of the upper plate, and a plurality of guide blocks are evenly arranged on the end surface of the lower shoulder B; the cooling plate comprises a cooling tube mounting plate and a graphite heat-uniform layer upper cover, a cooling pipeline is arranged in the cooling tube mounting plate, a graphite heat-uniform layer is arranged in the graphite heat-uniform layer upper cover, and a plurality of adjusting bolts are evenly distributed in the middle of the cooling plate; the adjusting bolt passes downward through the inner hole of the support shaft and the guide block slot, and the plurality of adjusting bolts are fixed by a fixing block. The present invention has an ingenious and reasonable structure, is convenient for adjusting the distance between the cooling plate and the heating tube, is suitable for a variety of process environments, can greatly adjust the cooling capacity of the wafer heater, effectively improves production efficiency, greatly reduces costs, and increases service life.

Description

Technical Field

[0001] The invention relates to the field of semiconductor chip processing, and in particular to a PECVD wafer heater capable of greatly adjusting cooling capacity. Background Art

[0002] With the rapid development of semiconductor chip technology, the semiconductor foundry industry is highly competitive. Semiconductor production equipment faces the challenge of diversified processes. The original equipment needs to use more advanced processes. Wafer fabs need a lower cost competitive advantage and must use existing equipment to meet the diverse process requirements of customers in order to adapt to diversified competition and stay ahead in the industry.

[0003] (PECVD) Wafer heater is a key equipment for semiconductor chip processing. It plays the role of carrying and adsorbing wafers and providing heating. As the RF process power increases, the wafer heater will continue to absorb heat during the process, causing the temperature of the wafer heater to continue to rise. The cooling efficiency of the heater itself cannot be effectively adjusted, resulting in a longer time for the heater to reach a stable temperature, resulting in a decrease in the production efficiency of semiconductor chips (ICs), which seriously affects product quality.

[0004] Since the temperature of the wafer heater cannot be kept stable, the process is unstable and scrapping is difficult to prevent. In addition, the expensive heaters are unable to adapt to more advanced RF processes and need to be replaced with complex heaters according to different processes. The heaters have poor versatility and high costs. Therefore, it is very urgent to find improved methods to control the temperature of the wafer heater to ensure that it is not affected by the ever-increasing power process, to offset the heat generated by the RF in time, to improve IC production efficiency and reduce costs.

[0005] Based on the above reasons, it is necessary to take plasma enhanced chemical vapor deposition (PECVD) as the research object and study how to overcome the existing problems through design optimization as the process requirements increase. Summary of the invention

[0006] The object of the present invention is to solve the above technical problems and provide a wafer heater with greatly adjustable cooling capacity.

[0007] In order to achieve the above technical objectives and meet the above technical requirements, the technical solution adopted by the present invention is: a wafer heater with greatly adjustable cooling capacity, including an upper plate, characterized in that: an armored heating tube is embedded in the top surface of the inner hole of the upper plate, and a temperature measuring thermocouple is arranged in the middle of the upper plate; a cover plate, a cooling plate and a support shaft are arranged in the inner hole of the upper plate from top to bottom; the upper shoulder A of the support shaft is clamped at the lower end of the upper plate, and a plurality of guide blocks are evenly arranged on the end surface of the lower shoulder B; the cooling plate includes a cooling tube mounting plate and a graphite uniform heating layer upper cover, a cooling pipeline is arranged in the cooling tube mounting plate, and a graphite uniform heating layer lower cover, a graphite uniform heating layer and a graphite uniform heating layer upper cover are arranged in sequence on the top surface of the cooling tube mounting plate; a plurality of adjusting bolts are evenly distributed on the bottom of the cooling tube mounting plate; the adjusting bolts pass downward through the inner hole of the support shaft and the guide block slot, and the plurality of adjusting bolts are fixed by a fixing block.

[0008] Preferably: the top surface of the upper plate is evenly distributed with a plurality of small bosses and air uniforming grooves, the bottom surface of the upper plate is provided with an inner hole, the top surface of the inner hole is provided with a mounting groove for the armored heating pipe, the mouth surface of the inner hole is provided with a stepped hole for installing the support shaft, a plurality of columns extend downward from the top surface of the inner hole of the upper plate, ejector holes are provided in the columns, and the ejector holes extend from the top surface of the upper plate to the top surface of the small bosses.

[0009] Preferably, two temperature measuring heads are arranged inside the temperature measuring thermocouple, and the top surface of the temperature measuring thermocouple is 2-3 mm away from the top surface of the upper plate.

[0010] Preferably, the depth of the inner hole is 10-20 mm greater than the sum of the thicknesses of the cooling tube mounting plate, the graphite heat-leveling layer upper cover and the cover plate.

[0011] Preferably: the adjusting bolt is connected to the cooling plate via threads; and the guide block is provided with a waist-shaped groove for radially limiting the adjusting bolt.

[0012] Preferably, the adjusting bolt is configured to be clearance-fitted with the fixing block and the guide block.

[0013] Preferably, the upper plate and the support shaft are welded by laser, and a nickel plating layer of 15 to 25 microns is provided on the outer periphery of the upper plate and the support shaft.

[0014] Preferably, the cooling tube mounting plate is made of stainless steel, the graphite heat-uniform layer upper cover is made of copper, and the cooling tube mounting plate and the graphite heat-uniform layer upper cover are connected by brazing.

[0015] Preferably, the top surface of the upper plate 1 except the top surface of the small boss 1-2 is sandblasted to Ra3-5; the top surface of the small boss 1-2 is ground to ensure that the roughness is within Ra0.4.

[0016] Beneficial effects of the present invention:

[0017] 1. An adjustment structure is set inside the cooling plate to facilitate the adjustment of the distance between the cooling plate and the heating tube. It is suitable for a variety of process environments, has a large adjustment range, and can greatly adjust the cooling capacity of the wafer heater, effectively improving production efficiency and significantly reducing costs.

[0018] 2. There are two temperature measuring heads inside the thermocouple, which are used to measure temperature and monitor temperature changes, so as to control the wafer temperature more accurately.

[0019] 3. The top surface of the upper plate is provided with an air-uniform groove and a small boss. The air-uniform groove prevents the wafer from sliding during the process to ensure process stability. The small boss ensures a certain gap between the wafer and the upper plate to improve the temperature uniformity of the wafer surface. The surface of the small boss is ground to ensure that the roughness is within Ra0.4 to prevent scratches on the wafer. The top surface of the upper plate except the top surface of the small boss is sandblasted to Ra3-5 to improve the thermal radiation capacity and enhance the uniformity of the wafer.

[0020] 4. The upper plate and the outer periphery of the support shaft are provided with a 15~25 micron nickel plating layer to ensure good corrosion and oxidation resistance and improve service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the structure of the present invention;

[0022] Figure 2 for Figure 1 A top view of

[0023] Figure 3 It is a schematic diagram of the front view of the upper plate in the present invention;

[0024] Figure 4 It is a schematic diagram of a rear view of the upper plate in the present invention;

[0025] Figure 5 for Figure 3 Middle BB section view;

[0026] Figure 6 It is a schematic diagram of the cooling plate structure in the present invention;

[0027] Figure 7 for Figure 6 A top view of

[0028] Figure 8 for Figure 6 The enlarged image at point I in the middle;

[0029] Fig. 9 This is a schematic diagram of the support shaft structure in the present invention;

[0030] Fig.10 for Fig. 9 A schematic top view of

[0031] Fig.11for Fig. 9 A bottom view schematic diagram of ;

[0032] In the figure: 1. Upper plate, 1-1. Upper plate body, 1-2. Small boss, 1-3. Mounting hole, 1-4. Ejector hole, 1-5. Mounting groove, 1-6. Air uniformity groove, 1-7. Column, 1-8. Inner hole, 2. Cooling plate, 2-1. Cooling pipeline, 2-2. Graphite heat uniformity layer, 2-3. Adjusting bolt, 2-4. Fixing block, 2-5, Cooling pipe mounting plate, 2-6, Graphite heat uniformity layer upper cover, 2-7. Graphite heat uniformity layer lower cover 3. Support shaft, 3-1. Support shaft body, 3-2. Sealing ring mounting groove, 3-3. Sealing ring locking threaded hole, 3-4. Guide block, 4. Armored heating pipe, 5. Cover plate, 6. Temperature measuring thermocouple. DETAILED DESCRIPTION

[0033] The present invention will be further described below in conjunction with the accompanying drawings.

[0034] In the figure: a wafer heater with greatly adjustable cooling capacity, comprising an upper plate 1, characterized in that: an armored heating tube 4 is embedded in the top surface of the inner hole of the upper plate 1, and a temperature measuring thermocouple 6 is arranged in the middle of the upper plate 1; a cover plate 5, a cooling plate 2 and a support shaft 3 are arranged in the inner hole of the upper plate 1 from top to bottom; the upper shoulder A of the support shaft 3 is clamped at the lower end of the upper plate 1, and a plurality of guide blocks 3-4 are evenly arranged on the end surface of the lower shoulder B; the cooling plate 2 includes a cooling tube mounting plate 2-5 and a graphite uniform A heat layer upper cover 2-6, a cooling pipe 2-1 is arranged in the cooling pipe mounting plate 2-5, and a graphite heat-uniform layer lower cover 2-7, a graphite heat-uniform layer 2-2, and a graphite heat-uniform layer upper cover 2-6 are arranged in sequence on the top surface of the cooling pipe mounting plate 2-5; a plurality of adjusting bolts 2-3 are evenly distributed on the bottom of the cooling pipe mounting plate 2-5; the adjusting bolts 2-3 pass downward through the inner hole of the support shaft 3 and the slot of the guide block 3-4, and the plurality of adjusting bolts 2-3 are fixed by the fixing block 2-4.

[0035] In this preferred embodiment, the top surface of the upper plate 1 is evenly distributed with a plurality of small bosses 1-2 and gas uniforming grooves 1-6, the bottom surface of the upper plate 1 is provided with an inner hole 1-8, the top surface of the inner hole 1-8 is provided with a mounting groove 1-5 for the armored heating pipe 4, the mouth surface of the inner hole 1-8 is provided with a stepped hole for mounting the support shaft 3, a plurality of columns 1-7 are extended downward from the top surface of the inner hole of the upper plate 1, and a pinhole hole 1-4 is provided in the column 1-7, and the pinhole hole 1-4 extends from the top surface of the upper plate 1 to the top surface of the small boss 1-2.

[0036] In this preferred embodiment, two temperature measuring heads are arranged inside the temperature measuring thermocouple 6 , and the top surface of the temperature measuring thermocouple 6 is 2-3 mm away from the top surface of the upper plate 1 .

[0037] In this preferred embodiment, the depth of the inner hole 1-8 is 10-20 mm greater than the sum of the thicknesses of the cooling tube mounting plate 2-5, the graphite heat-uniform layer upper cover 2-6 and the cover plate 5.

[0038] In this preferred embodiment, the adjusting bolt 2 - 3 is connected to the cooling plate 2 via threads; and the guide block 3 - 4 is provided with a waist-shaped groove for radially limiting the adjusting bolt 2 - 3 .

[0039] In this preferred embodiment, the adjusting bolt 2 - 3 is configured to be clearance-fitted with the fixing block 2 - 4 and the guide block 3 - 4 .

[0040] In this preferred embodiment, the upper plate 1 and the support shaft 3 are welded by laser, and a nickel plating layer of 15 to 25 microns is provided on the outer periphery of the upper plate 1 and the support shaft 3.

[0041] In this preferred embodiment, the cooling tube mounting plate 2-5 is made of stainless steel, the graphite heat-uniform layer upper cover 2-6 is made of copper, and the cooling tube mounting plate 2-5 and the graphite heat-uniform layer upper cover 2-6 are connected by brazing.

[0042] In this preferred embodiment, the top surface of the upper plate 1 except the top surface of the small boss 1-2 is sandblasted to Ra3-5; the top surface of the small boss 1-2 is ground to ensure that the roughness is within Ra0.4.

[0043] During specific implementation, the armored heating tube 4 with a cross-section of approximately square is embedded in the armored heating tube mounting groove 1-5 of the wafer heater upper plate body 1, and the heating tube cover plate 5 and the wafer heater upper plate body 1 are welded together by vacuum brazing, the cooling pipe 2-1 is embedded in the cooling tube mounting plate 2-5, the graphite uniform heating layer 2-2 is assembled between the cooling tube mounting plate 2-5 and the graphite uniform heating layer upper cover 2-6 by welding, the graphite uniform heating layer upper cover 2-6 and the graphite uniform heating layer lower cover 2-7 are connected by laser welding, the combined adjusting bolt 2-3 on the cooling plate 2 is connected to the support shaft 3, the support shaft 3 is sealed and connected to the wafer heater upper plate body 1 by laser welding, and a sealing ring is used through the sealing ring mounting groove 3-2 to ensure the sealed vacuum.

[0044] Working principle: During the chip processing, the heat generated by the radio frequency is transferred to the upper plate body 1 of the wafer heater, and the temperature of the wafer heater rises rapidly. At this time, the distance between the cooling plate 2 and the armored heating tube 4 is adjusted by adjusting the bolts 2-3, and the distance between it and the armored heating tube 4 is controlled by the temperature measuring thermocouple 6. Under the action of the cooling plate 2, the large amount of heat generated by the radio frequency process is offset in time to ensure the temperature stability of the wafer heater during the process. Using a wafer heater can be competent for a variety of process environments, without the need to replace expensive wafer heaters of different models, and the adjustment is simple, which effectively improves production efficiency and ensures a significant reduction in costs.

[0045] The above embodiments of the present invention are merely examples to clearly illustrate the present invention, but are not intended to limit the protection scope of the present invention. All equivalent technical solutions also belong to the scope of the present invention. The patent protection scope of the present invention should be defined by the claims.

Claims

1. A wafer heater with a cooling capacity that can be adjusted to a large extent, comprising an upper plate (1), characterized in that: An armored heating tube (4) is embedded in the top surface of the inner hole of the upper plate (1), and a temperature measuring thermocouple (6) is arranged in the middle of the upper plate (1); a cover plate (5), a cooling plate (2) and a support shaft (3) are arranged in the inner hole of the upper plate (1) from top to bottom; the upper shoulder A of the support shaft (3) is clamped on the lower end of the upper plate (1), and a plurality of guide blocks (3-4) are evenly arranged on the end surface of the lower shoulder B; the cooling plate (2) comprises a cooling tube mounting plate (2-5) and a graphite uniform heat layer upper cover (2-6); the cooling tube mounting plate (2-5) and the cooling tube mounting plate (2-6) are provided with a plurality of guide blocks (3-4) on the upper shoulder B of the support shaft (3); the cooling tube mounting plate (2-5) and the graphite uniform heat layer upper cover (2-6) are provided with a plurality of guide blocks (3-4) on the lower ... A cooling pipeline (2-1) is arranged in the mounting plate (2-5); a graphite heat-uniform layer lower cover (2-7), a graphite heat-uniform layer (2-2), and a graphite heat-uniform layer upper cover (2-6) are arranged in sequence on the top surface of the cooling pipe mounting plate (2-5); a plurality of adjusting bolts (2-3) are evenly distributed on the bottom of the cooling pipe mounting plate (2-5); the adjusting bolts (2-3) pass downward through the inner hole of the support shaft (3) and the slot of the guide block (3-4), and the plurality of adjusting bolts (2-3) are fixed by the fixing block (2-4); The top surface of the upper plate (1) is evenly distributed with a plurality of small bosses (1-2) and uniform air grooves (1-6); the bottom surface of the upper plate (1) is provided with an inner hole (1-8); the top surface of the inner hole (1-8) is provided with a mounting groove (1-5) for the armored heating pipe (4); the mouth surface of the inner hole (1-8) is provided with a stepped hole for mounting the support shaft (3); the top surface of the inner hole of the upper plate (1) is provided with a plurality of columns (1-7) extending downward; the columns (1-7) are provided with ejector holes (1-4); the ejector holes (1-4) extend from the top surface of the upper plate (1) to the top surface of the small bosses (1-2); The top surface of the upper plate (1) except the top surface of the small boss (1-2) is sandblasted to Ra3-5; the top surface of the small boss (1-2) is ground to ensure that the roughness is within Ra0.

4.

2. The wafer heater with greatly adjustable cooling capacity according to claim 1, characterized in that: Two temperature measuring heads are arranged inside the temperature measuring thermocouple (6), and the top surface of the temperature measuring thermocouple (6) is 2-3 mm away from the top surface of the upper plate (1).

3. The wafer heater with greatly adjustable cooling capacity according to claim 1, characterized in that: The depth of the inner hole (1-8) is 10 to 20 mm greater than the sum of the thicknesses of the cooling tube mounting plate (2-5), the graphite heat-uniform layer upper cover (2-6) and the cover plate (5).

4. The wafer heater with greatly adjustable cooling capacity according to claim 1, characterized in that: The adjusting bolt (2-3) is connected to the cooling plate (2) via threads; and the guide block (3-4) is provided with a waist-shaped groove for radially limiting the adjusting bolt (2-3).

5. The wafer heater with greatly adjustable cooling capacity according to claim 1, characterized in that: The adjusting bolt (2-3) is configured to be clearance-fitted with the fixing block (2-4) and the guide block (3-4).

6. The wafer heater with greatly adjustable cooling capacity according to claim 1, characterized in that: The upper plate (1) and the support shaft (3) are welded by laser welding, and a nickel plating layer of 15 to 25 micrometers is provided on the outer periphery of the upper plate (1) and the support shaft (3).

7. The wafer heater with greatly adjustable cooling capacity according to claim 1, characterized in that: The cooling tube installation plate (2-5) is made of stainless steel, the graphite heat-uniform layer upper cover (2-6) is made of copper, and the cooling tube installation plate (2-5) and the graphite heat-uniform layer upper cover (2-6) are connected by brazing.

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