Heating lamp assembly and semiconductor process chamber
By placing a lens between the heating lamp and the chamber body, the light emitted by the heating lamp is made into parallel light, which solves the problem of uneven film thickness in wafer deposition and achieves a more uniform temperature field distribution and higher film flatness.
Patent Information
- Application Number
- CN202411147194.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-20
- Publication Date
- 2026-03-03
AI Technical Summary
In existing CVD silicon epitaxy equipment, the thickness of the film deposited on the wafer is uneven, resulting in a wavy distribution that fails to meet flatness requirements and affects the quality of subsequent processes.
A lens is placed between the heating lamp and the chamber body so that the light emitted by the heating lamp forms parallel light after passing through the lens and evenly illuminates the base or wafer, ensuring that the energy density distribution of each heating lamp is uniform.
By using lenses, the temperature field distribution in the radial direction of the wafer is made uniform, which alleviates the difference in film thickness and improves the flatness of the film.
Smart Images
Figure CN121593036A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of semiconductor process equipment, and more particularly to a heating lamp assembly and a semiconductor process chamber. Background Technology
[0002] With the advancement of semiconductor technology, silicon epitaxy plays an increasingly important role in integrated circuit manufacturing. Chemical vapor deposition (CVD) silicon epitaxy equipment is a key production facility that can grow high-quality silicon thin films on wafer surfaces. In this process, the temperature field provided by the heating lamps and the gold-plated reflective screen is one of the most critical factors affecting process quality. The stability, uniformity, and adjustability of the temperature field are crucial to the quality of the silicon epitaxial film, especially in thick-film processes, where non-uniform temperature fields can lead to various defects such as slip lines, severely impacting product quality. Currently, CVD silicon epitaxy equipment commonly uses long, strip-shaped heating lamps, which, in conjunction with the gold-plated reflective screen, form a strip-shaped temperature field to heat the rotating wafer.
[0003] Multiple elongated heating lamps are distributed along the diameter of the wafer. The energy from each lamp is relatively uniformly distributed along the circumference of the wafer. However, the temperature field formed by the multiple lamps in the radial direction resembles a wave function distribution, resulting in a wavy film thickness profile deposited under a stable gas flow. This wavy film thickness profile prevents the deposited film from meeting flatness requirements, thus affecting subsequent processes such as photolithography and etching. Summary of the Invention
[0004] This invention discloses a heating lamp assembly and a semiconductor process chamber to solve the problem in related technologies that the film layer deposited on the wafer cannot meet the flatness requirements.
[0005] To solve the above-mentioned technical problems, the present invention is implemented as follows:
[0006] In a first aspect, this application discloses a heating lamp assembly applied in a semiconductor process chamber. The semiconductor process chamber includes a chamber body and a base, the base being disposed within the chamber body. The heating lamp assembly includes a plurality of strip heating lamps arranged along a first direction and a plurality of lenses corresponding one-to-one with the plurality of strip heating lamps, wherein:
[0007] The lens is located between the strip heating lamp and the chamber body, and the lens is used to direct the light rays from the corresponding strip heating lamp onto the base in a parallel manner.
[0008] Secondly, this application also discloses a semiconductor process chamber, which includes a chamber body, a base disposed within the chamber body, and the heating lamp assembly described in the first aspect. The plurality of strip heating lamps and the plurality of lenses are all located outside the chamber body, and the lenses are located between the strip heating lamps and the chamber body.
[0009] The technical solution adopted in this invention can achieve the following technical effects:
[0010] The heating lamp assembly disclosed in this application provides multiple lenses correspondingly arranged between multiple strip heating lamps and the chamber body. This allows the light emitted by the multiple strip heating lamps to pass through the corresponding lenses and form parallel light that is projected onto the base or the wafer on the base. As a result, the light emitted by the strip heating lamps is projected onto the base or the wafer on the base at the same angle after passing through the lenses. Therefore, the energy density distribution of each strip heating lamp projecting onto the base or the wafer on the base is relatively uniform. Consequently, when the multiple strip heating lamps heat the wafer on the base, the temperature field distribution of the wafer in the radial direction is relatively uniform. This can alleviate the thickness difference of the film deposited on the wafer in the radial direction during film deposition, thereby improving the flatness of the film deposited on the wafer. Attached Figure Description
[0011] Figure 1 This is a schematic diagram of the optical path of the heating lamp assembly disclosed in an embodiment of the present invention;
[0012] Figure 2 This is a schematic diagram of the structure of a semiconductor process chamber disclosed in an embodiment of the present invention;
[0013] Figure 3 This is a schematic diagram of the lens disclosed in an embodiment of the present invention;
[0014] Figure 4 This is a schematic diagram of the structure of the heating lamp assembly disclosed in an embodiment of the present invention;
[0015] Figure 5 This is an equivalent schematic diagram of light rays from a light source passing through a lens at the far focal point. The elliptical structure is equivalent to a lens, n1 represents the refractive index of the lens, and n2 represents the refractive index of the environment in which the lens is located.
[0016] Explanation of reference numerals in the attached figures:
[0017] 100-chamber body, 110-top wall,
[0018] 200-base,
[0019] 300-strip heating lamp,
[0020] 400 - Lens, 411 - First arc segment, 412 - Elliptical segment
[0021] 500 - Reflector, 510 - Second arc segment. Detailed Implementation
[0022] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below in conjunction with specific embodiments and corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.
[0023] The technical solutions disclosed in the various embodiments of the present invention will be described in detail below with reference to the accompanying drawings.
[0024] Please refer to Figures 1 to 5 This invention discloses a heating lamp assembly applied in a semiconductor process chamber, which can be a chamber for silicon epitaxial growth using chemical vapor deposition. The disclosed semiconductor process chamber includes a chamber body 100 and a base 200. The chamber body 100 can be a site for growing a silicon thin film on a wafer surface. The base 200 is disposed within the chamber body 100 and is used to support the wafer. The base 200 can rotate while carrying the supported wafer.
[0025] The heating lamp assembly includes a plurality of strip heating lamps 300 arranged along a first direction and a plurality of lenses 400 corresponding to each of the strip heating lamps 300. The strip heating lamps 300 can be cylindrical, prismatic, or other structures; this application embodiment does not limit the type of strip heating lamp 300. The first direction can be parallel to the chamber wall (hereinafter referred to as the top wall 110) of the chamber body 100 opposite to the strip heating lamps 300.
[0026] The lens 400 is located between the strip heating lamp 300 and the chamber body 100. It should be noted that the lens 400 is also a strip structure, and the length of the lens 400 is adapted to the length of the strip heating lamp 300.
[0027] For example, the heating lamp assembly can be disposed outside the chamber body 100. Specifically, the heating lamp assembly can be located above the chamber body 100, below the chamber body 100, or both above and below the chamber body 100. When the heating lamp assembly is located above the chamber body 100, the top wall 110 of the chamber body 100 is formed of a light-transmitting material. When the heating lamp assembly is located below the chamber body 100, the bottom wall of the chamber body 100 is formed of a light-transmitting material.
[0028] Taking the heating lamp assembly located above the chamber body 100 as an example, multiple strip heating lamps 300 can be opposite to the top wall 110 of the chamber body 100, and the bearing surface of the base 200 can be opposite to the top wall 110. The top wall 110 can be a transparent structure, the top wall 110 can be made of quartz material, and of course, the top wall 110 can also be made of other materials. This application embodiment does not limit the material of the top wall 110.
[0029] Lens 400 is used to direct the light rays from the corresponding strip heating lamp 300 onto the base 200 in a parallel manner. Parallel light rays onto the base 200 means that multiple light rays projected from the strip heating lamp 300 onto lens 400 are combined into parallel rays after passing through lens 400 and then directed onto the base 200. The light rays emitted outward from the wavefront of the strip heating lamp 300 are radially distributed. The radially distributed light rays from the strip heating lamp 300 onto lens 400 are converged by lens 400 to form parallel rays. The light rays can pass through the chamber body 100 and be projected onto the base 200 to heat the base 200 or the wafer on the base 200. The light rays can be directed perpendicularly or obliquely towards the base 200; this embodiment does not specifically limit the angle at which the light rays are directed towards the base 200.
[0030] It should be noted that the arrangement of the multiple strip heating lamps 300 and the multiple lenses 400 must satisfy the requirement that the parallel light formed by the light emitted by the multiple strip heating lamps 300 after passing through the multiple lenses 400 illuminates the area of the base 200 or the wafer on the base 200 continuously. That is, the areas of the base 200 or the wafer on the base 200 illuminated by two adjacent strip heating lamps 300 after passing through the lens 400 are connected.
[0031] To facilitate understanding of the technical solution of this application, we first analyze the case where multiple strip heating lamps directly irradiate the substrate or the wafer on the substrate without passing through a lens. The light emitted from the wave array of the strip heating lamps is radially distributed. When a cylindrical energy wave array contacts a plane, the energy density on the plane is distributed as an arctan function, meaning the energy density is highest at the position perpendicular to the light beam, and gradually decreases as the angle between the light beam and the plane decreases. Therefore, the energy distribution in the area between two adjacent strip heating lamps on the plane gradually decreases from the position directly opposite the two lamps towards the middle. When multiple strip heating lamps heat the wafer on the substrate, a temperature field similar to a wave function is formed. This results in a wavy pattern during wafer deposition, causing the deposited film to fail to meet the flatness requirements.
[0032] The heating lamp assembly disclosed in this application provides a plurality of lenses 400 correspondingly disposed between a plurality of strip heating lamps 300 and the chamber body 100. This allows the light emitted by the plurality of strip heating lamps 300 to pass through the corresponding lenses 400 and form parallel light that is projected onto the base 200 or the wafer on the base 200. As a result, the light emitted by the strip heating lamps 300 is projected onto the base 200 or the wafer on the base 200 at the same angle after passing through the lenses 400. Therefore, the energy density distribution of each strip heating lamp 300 projecting onto the base 200 or the wafer on the base 200 is relatively uniform. Consequently, when the plurality of strip heating lamps 300 heat the wafer on the base 200, the temperature field distribution of the wafer in the radial direction is relatively uniform. This can alleviate the thickness difference of the film deposited on the wafer in the radial direction during film deposition, thereby improving the flatness of the film deposited on the wafer.
[0033] Specifically, the lens 400 can be a lens that is convex on both sides. After the positions of the strip heating lamp 300 and the lens 400 are set, the lens 400 only needs to ensure that the light rays from the strip heating lamp 300 illuminating the lens 400 can be emitted parallel to each other. The specific parameters of the lens 400 (including geometric parameters, optical parameters, etc.) can be selected according to actual needs, and this embodiment does not impose any restrictions on this.
[0034] In another embodiment, the lens 400 may have a first concave surface and a convex surface distributed opposite to each other. The projection of the first concave surface in the second direction may be a first arc segment 411, and the projection of the convex surface in the second direction may be an elliptical segment 412. The dot of the first arc segment 411 and the far-end focus of the elliptical segment 412 may converge at the strip heating lamp 300. This convergence means that the dot of the first arc segment 411 and the far-end focus of the elliptical segment 412 converge within the projection area of the strip heating lamp 300 in the second direction or at the center of the projection area. The length direction of the strip heating lamp 300 may be parallel to the second direction.
[0035] The second direction can be parallel to the chamber wall of the chamber body 100 opposite to the strip heating lamp 300, and the second direction can be perpendicular to the first direction.
[0036] The heating lamp assembly disclosed in this application configures the lens 400 with a first concave surface and a convex surface distributed in opposite directions. The projection of the first concave surface in the second direction is a first arc segment 411, and the projection of the convex surface in the second direction is an elliptical segment 412. This allows the dot of the first arc segment 411 and the far focal point of the elliptical segment 412 to converge at the strip heating lamp 300. Since the strip heating lamp 300 is located at the dot of the first arc segment 411, the light emitted from the strip heating lamp 300 can enter the lens 400 perpendicularly from the first concave surface without refraction. Since the strip heating lamp 300 is located at the far focal point of the elliptical segment 412, the light entering the lens 400 can exit parallel from the convex surface side. This makes it easier to set the relative position of the strip heating lamp 300 and the lens 400, and to select the lens 400.
[0037] It should be noted that the eccentricity of the elliptical segment 412 is related to the refractive index of lens 400 and the refractive index of the environment in which lens 400 is located (for example, if lens 400 is in air, then it is the refractive index of air). For a detailed explanation, please refer to [link to relevant documentation]. Figure 5 The focal point F1 can be the location of the strip heating lamp 300. According to geometric principles, n1*F1A + n2*AD = constant, where n1 represents the refractive index of lens 400, n2 represents the refractive index of the environment in which lens 400 is located, F1A represents the optical path length of light propagating in lens 400, and AD represents the optical path length of light propagating in the environment in which lens 400 is located. Based on n1*F1A + n2*AD = constant 1, we can deduce that F1A + (n2 / n1)*AD = constant 2. Since n1 > n2, n2 / n1 < 1. Therefore, n2 / n1 can be used as the eccentricity e of the elliptical segment 412, thus revealing the shape of the elliptical segment 412. The trajectory of point A is an ellipse. At this point, the light emitted by the strip heating lamp 300 at focal point F1 can form parallel light after refraction.
[0038] Specifically, lens 400 can be made of quartz, which has a refractive index of about 1.4. The environment in which lens 400 is located can be air, which has a refractive index of about 1. Therefore, the eccentricity of the elliptical line segment 412 can be 1 / 1.4.
[0039] To simplify the structure of the lens 400, the two endpoints of the first arc segment 411 may coincide with the two endpoints of the elliptical segment 412, thus eliminating the need for other transitional connecting surfaces at the two endpoints of the first arc segment 411 and the two endpoints of the elliptical segment 412, thereby simplifying the structure of the lens 400.
[0040] Of course, the two endpoints of the first arc segment 411 and the two endpoints of the elliptical segment 412 can be connected by a plane or an arc surface. This application embodiment does not limit the structure of the lens 400 at the two endpoints of the first arc segment 411 and the two endpoints of the elliptical segment 412.
[0041] Since the bearing surface of the base 200 is a plane, the angle at which the light emitted by the strip heating lamp 300 can be projected onto the bearing surface varies depending on the distance between the strip heating lamp 300 and the bearing surface. In order to allow more light to be projected onto the base 200 or the chip on the base 200, optionally, the central angle corresponding to the first arc segment 411 is greater than or equal to 60° and less than or equal to 90°, making the central angle corresponding to the first arc segment 411 relatively large, thereby allowing more light emitted by the strip heating lamp 300 to be projected onto the base 200 or the chip on the base 200.
[0042] In order to make full use of the light emitted by the strip heating lamp 300, the heating lamp assembly may optionally include a reflector 500. The reflector 500 may be disposed on the side of the strip heating lamp 300 away from the lens 400. The reflector 500 is used to reflect the light emitted by the strip heating lamp 300 that is directed toward the reflector 500 back to the side where the lens 400 is located.
[0043] The heating lamp assembly disclosed in this application provides a reflector 500 on the side of the strip heating lamp 300 away from the lens 400. This allows light emitted from the strip heating lamp 300 and directed toward the reflector 500 to be reflected back to the side where the lens 400 is located. Consequently, some of the light emitted from the strip heating lamp 300 away from the base 200 can be reflected back to the base 200 or the wafer on the base 200 after being reflected by the reflector 500. This allows for more efficient use of the light emitted from the strip heating lamp 300 and better heating of the base 200 or the wafer on the base 200.
[0044] Specifically, the reflector 500 can be a plane mirror. Using a plane mirror makes the structure of the reflector 500 relatively simple.
[0045] In another embodiment, the reflector 500 may have a plurality of second concave surfaces arranged along the first direction, and the plurality of second concave surfaces may be arranged one-to-one with a plurality of strip heating lamps 300. The projection of the second concave surface in the second direction may be a second arc segment 510, and the dot of the second arc segment 510 may be located at the strip heating lamp 300.
[0046] The heating lamp assembly disclosed in this application configuration has a structure in which the reflector 500 is configured to have a plurality of second concave surfaces arranged along a first direction, such that each second concave surface corresponds one-to-one with a plurality of strip heating lamps 300, and the projection of the second concave surface in the second direction is a second arc segment 510, so that the dot of the second arc segment 510 is located at the strip heating lamp 300. This allows the light illuminating the second concave surface from the strip heating lamp 300 to return along the same path after being reflected by the second concave surface and passing through the strip heating lamp 300. After being shaped by the lens 400, it forms parallel light that illuminates the base 200 or the wafer on the base 200. This not only improves the heating capacity of the base 200 or the wafer on the base 200, but also better ensures the uniformity of energy density distribution.
[0047] In order to allow more light to be projected onto the base 200 or the chip on the base 200, optionally, the central angle corresponding to the second arc segment 510 can be greater than or equal to 60° and less than or equal to 90°, so that the central angle corresponding to the second arc segment 510 is relatively large, thereby reflecting more light onto the base 200 or the chip on the base 200, thereby improving the heating capacity of the base 200 or the chip on the base 200.
[0048] To improve the stability of the relative positions between the multiple lenses 400, the multiple lenses 400 can optionally be connected sequentially along the first direction to form an integral structure, thereby stabilizing the relative positions between the multiple lenses 400, and the integral structure is beneficial for the installation of the multiple lenses 400.
[0049] This application also discloses a semiconductor process chamber, which includes a chamber body 100, a base 200 disposed within the chamber body 100, and a heating lamp assembly disclosed in the above embodiments. Multiple strip heating lamps 300 and multiple lenses 400 are located outside the chamber body 100 and opposite to the top wall 110 of the chamber body 100. The lenses 400 are located between the strip heating lamps 300 and the chamber body 100. The lenses 400 are used to make the light rays irradiated by the corresponding strip heating lamps 300 onto the lens 400 be directed parallel to the base 200.
[0050] The semiconductor process chamber disclosed in this application provides a heating lamp assembly as described in the above embodiments, which makes the temperature field distribution of the wafer in the radial direction relatively uniform when multiple strip heating lamps 300 heat the wafer on the base 200. This can alleviate the thickness difference of the film deposited on the wafer in the radial direction during film deposition, thereby improving the flatness of the film deposited on the wafer.
[0051] Optionally, the semiconductor process chamber may include two sets of heating lamp assemblies; wherein, one set of heating lamp assemblies may be located above the chamber body 100, and the other set of heating lamp assemblies may be located below the chamber body 100. Specifically, the heating lamp assembly located above the chamber body 100 may be a first heating lamp assembly, and the heating lamp assembly located below the chamber body 100 may be a second heating lamp assembly.
[0052] The light from the strip heating lamp 300 of the heating lamp assembly located above the chamber body 100, illuminating the lens 400, is directed parallel to the top surface of the base 200. Similarly, the light from the strip heating lamp 300 of the heating lamp assembly located below the chamber body 100, illuminating the lens 400, is directed parallel to the bottom surface of the base 200. The top and bottom surfaces of the base 200 are opposite to each other, and the top surface of the base 200 can be used to support a wafer.
[0053] The semiconductor process chamber disclosed in this application provides heating lamp assemblies above and below the chamber body 100. The light emitted by the two sets of heating lamp assemblies passes through the top wall 110 and the bottom wall of the chamber body 100 and is directed towards the top and bottom surfaces of the base 200, thereby heating the base 200 from the top and bottom surfaces and improving the heating capacity of the base 200.
[0054] In one specific embodiment, when setting the heating lamp assembly above the chamber body 100, the strip heating lamp 300 can be positioned within a range of 150mm to 200mm from the base 200 or the wafer on the base 200, including 150mm and 200mm. The diameter of the strip heating lamp 300 can be 10mm to 15mm, including 10mm and 15mm. The radius of the second arc segment 510 is related to the distance between two adjacent strip heating lamps 300. For example, when the central angle of the second arc segment 510 is 90°, the distance between two adjacent strip heating lamps 300 can be 28mm, and the radius of the second arc segment 510 can be 20mm. Of course, the distance between two adjacent strip heating lamps 300 can be maintained between 20mm and 30mm, including 20mm and 30mm. In this embodiment, the distance between two adjacent strip heating lamps 300 is not specifically limited.
[0055] The above embodiments of the present invention focus on describing the differences between the various embodiments. As long as the different optimization features between the various embodiments are not contradictory, they can be combined to form a better embodiment. For the sake of brevity, they will not be described in detail here.
[0056] The embodiments of the present invention have been described above with reference to the accompanying drawings. However, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of the present invention without departing from the spirit and scope of the claims, and all of these forms are within the protection scope of the present invention.
Claims
1. A heating lamp assembly applied in a semiconductor process chamber, the semiconductor process chamber comprising a chamber body (100) and a base (200), the base (200) being disposed within the chamber body (100), characterized in that, The heating lamp assembly includes a plurality of strip heating lamps (300) arranged along a first direction and a plurality of lenses (400) corresponding one-to-one with the plurality of strip heating lamps (300), wherein: The lens (400) is located between the strip heating lamp (300) and the chamber body (100), and the lens (400) is used to make the light rays from the corresponding strip heating lamp (300) that are irradiated onto the lens (400) be directed parallel to the base (200).
2. The heating lamp assembly according to claim 1, characterized in that, The lens (400) has a first concave surface and a convex surface distributed opposite to each other. The projection of the first concave surface in the second direction is a first arc segment (411), and the projection of the convex surface in the second direction is an elliptical segment (412). The dot of the first arc segment (411) and the far-end focal point of the elliptical segment (412) converge at the strip heating lamp (300).
3. The heating lamp assembly according to claim 1, characterized in that, The two endpoints of the first arc segment (411) coincide with the two endpoints of the elliptical segment (412).
4. The heating lamp assembly according to claim 1, characterized in that, The central angle corresponding to the first arc segment (411) is greater than or equal to 60° and less than or equal to 90°.
5. The heating lamp assembly according to claim 1, characterized in that, The heating lamp assembly also includes a reflector (500), which is disposed on the side of the strip heating lamp (300) away from the lens (400) and is used to reflect the light emitted by the strip heating lamp (300) toward the reflector (500) to the side where the lens (400) is located.
6. The heating lamp assembly according to claim 5, characterized in that, The reflector (500) has a plurality of second concave surfaces arranged along the first direction. The plurality of second concave surfaces are arranged in a one-to-one correspondence with the plurality of strip heating lamps (300). The projection of the second concave surface in the second direction is a second arc segment (510). The dot of the second arc segment (510) is located at the strip heating lamp (300).
7. The heating lamp assembly according to claim 6, characterized in that, The central angle corresponding to the second arc segment (510) is greater than or equal to 60° and less than or equal to 90°.
8. The heating lamp assembly according to claim 6, characterized in that, The plurality of lenses (400) are connected in sequence along the first direction to form an integral structure.
9. A semiconductor process chamber, characterized in that, The assembly includes a chamber body (100), a base (200) disposed within the chamber body (100), and a heating lamp assembly according to any one of claims 1 to 8, wherein the plurality of strip heating lamps (300) and the plurality of lenses (400) are located outside the chamber body (100), and the lenses (400) are located between the strip heating lamps (300) and the chamber body (100).
10. The semiconductor process chamber according to claim 9, characterized in that, The semiconductor process chamber includes two sets of heating lamp assemblies; wherein one set of heating lamp assemblies is located above the chamber body (100), and the other set of heating lamp assemblies is located below the chamber body (100).