Method for improving temperature uniformity of annealing machine

Abstract

The application provides a method for improving temperature uniformity of an annealing machine, which comprises a base and a wafer supporting platform arranged on the base, a plurality of heating components are arranged in the base, the temperature of the area facing the heating components is higher than that of other areas around the heating components; a wafer is placed on the wafer supporting platform, the first temperature distribution on the wafer is measured and obtained, and whether the temperature uniformity of the annealing machine is qualified is judged; if the temperature uniformity of the annealing machine is not qualified, the orientation of the heating components is adjusted to improve the temperature uniformity of the annealing machine. By adjusting the orientation of the heating components, the temperature of the area between adjacent temperature probes is adjusted, and the temperature uniformity of the annealing machine is greatly improved.

Description

Technical Field

[0001] This invention relates to the field of integrated circuit manufacturing technology, and in particular to a method for improving the temperature uniformity of an annealing machine. Background Technology

[0002] Current integrated circuit manufacturing processes include multiple manufacturing steps, such as deposition, photolithography, etching, ion implantation, and planarization, to form corresponding semiconductor devices on wafers. In these manufacturing steps, wafers are often annealed for various reasons, such as repairing ion implantation damage, activating dopant ions, crystallizing amorphous materials, forming silicides, rearranging lattice structures, and relieving stress.

[0003] However, in the process of integrated circuit manufacturing, the stability of each annealing process (i.e., the stability of the annealing equipment used in each annealing process) directly affects the performance of semiconductor devices. Therefore, it is necessary to monitor the stability of the annealing process (especially temperature uniformity) to improve product yield.

[0004] In current processes, temperature uniformity within the process chamber of a back-illuminated annealing machine is typically monitored by measuring the sheet resistance (RS) of the wafer. Methods for measuring wafer sheet resistance include the Map method (121 points) and the Line method (49 points, i.e., a linear measurement method). When the Map method yields a poor result (No Good, NG), it indicates poor wafer temperature uniformity, which can be improved by adjusting the wafer's position within the process chamber using the transfer arm. Similarly, when the Line method yields a poor result, it also indicates poor temperature uniformity, which can be optimized by adjusting the power of heating components at different locations. However, adjusting the temperature probe offset only affects the temperature of the corresponding area. When overheating or undercooling occurs in the area between two adjacent temperature probes, this adjustment method is ineffective in improving wafer temperature uniformity.

[0005] Therefore, a method is needed to regulate the temperature in the middle region between adjacent temperature probes, thereby improving the temperature uniformity of the annealing machine. Summary of the Invention

[0006] The purpose of this invention is to provide a method for improving the temperature uniformity of an annealing machine, which involves adjusting the temperature of the area between adjacent temperature probes to improve the temperature uniformity of the annealing machine.

[0007] To achieve the above objectives, the present invention provides a method for improving the temperature uniformity of an annealing machine, comprising:

[0008] An annealing machine is provided, the annealing machine includes a base and a wafer carrier stage disposed on the base, the base is provided with a plurality of heating components, and the temperature of the area facing the heating components is higher than the temperature of other areas around the heating components;

[0009] A wafer is placed on the wafer carrier stage, the first temperature distribution on the wafer is measured and obtained, and it is determined whether the temperature uniformity of the annealing machine is qualified.

[0010] If the temperature uniformity of the annealing machine is not up to standard, the orientation of the heating component is adjusted to improve the temperature uniformity of the annealing machine.

[0011] Optionally, the annealing machine also includes multiple temperature probes, which are positioned above the wafer carrier stage. The distance between the temperature probes and the center of the wafer carrier stage is different for each temperature probe, so as to measure the temperature in the central circular area or the surrounding annular area where the temperature probe is located.

[0012] Optionally, if the temperature uniformity of the annealing machine is unqualified, the process of adjusting the orientation of the heating assembly includes:

[0013] If the temperature uniformity of the annealing machine is not up to standard, adjust the power of the heating component.

[0014] The second temperature distribution on the wafer is measured again, and the temperature uniformity of the annealing machine is judged again to be qualified; and,

[0015] If the temperature uniformity of the annealing machine is still not up to standard, then adjust the orientation of the heating component.

[0016] Optionally, the process of adjusting the power of the heating component includes:

[0017] Analyzing the first temperature distribution, the region with the highest and / or lowest temperature is designated as the first region to be adjusted; and,

[0018] Adjust the power of all heating components in the first area to be adjusted to improve the temperature uniformity of the annealing machine.

[0019] Optionally, the process of adjusting the orientation of the heating component includes:

[0020] Analyze the second temperature distribution, obtain the temperature difference between the temperatures measured by all adjacent temperature probes, and set the region corresponding to the two adjacent temperature probes with the largest temperature difference as the second region to be adjusted; and,

[0021] Adjust the orientation of all heating components in the second area to be adjusted to improve the temperature uniformity of the annealing machine.

[0022] Optionally, the process of adjusting the orientation of all heating components within the second area to be adjusted includes:

[0023] The two adjacent temperature probes with the largest temperature difference are defined as the first temperature probe and the second temperature probe, respectively. All heating components within the region corresponding to the first temperature probe are defined as the first heating component, and all heating components within the region corresponding to the second temperature probe are defined as the second heating component; and...

[0024] Adjust the orientation of the first heating component and the second heating component so that all the first heating components face the area corresponding to the second temperature probe, and all the second heating components face the area corresponding to the first temperature probe.

[0025] Optionally, the multiple heating components within the base are arranged in a honeycomb pattern. Each heating component includes a bulb and a lampshade surrounding the bulb. The lampshade is cylindrical, and the light emitted by the bulb exits from the top of the lampshade.

[0026] Optionally, the bulb includes a straight filament and a spiral filament, the extension direction of the straight filament and the spiral filament is the same as the axis of the lampshade, one end of the straight filament and the spiral filament are connected, and the other end is inserted into the base and electrically connected to the internal circuit of the base. The direction of the bulb closer to the straight filament is the orientation of the bulb.

[0027] Optionally, the first temperature distribution and the second temperature distribution on the wafer can be obtained by measuring the sheet resistance.

[0028] Optionally, the annealing machine includes a back-illuminated annealing machine and a front-illuminated annealing machine.

[0029] In summary, this invention provides a method for improving the temperature uniformity of an annealing machine. The annealing machine includes a base and a wafer carrier stage disposed on the base. Multiple heating elements are disposed within the base. The temperature of the area oriented towards the heating elements is higher than the temperature of other areas surrounding the heating elements. A wafer is placed on the wafer carrier stage, and a first temperature distribution on the wafer is measured to determine whether the temperature uniformity of the annealing machine is acceptable. If the temperature uniformity of the annealing machine is unacceptable, the orientation of the heating elements is adjusted to improve the temperature uniformity of the annealing machine. This invention, by adjusting the orientation of the heating elements, achieves temperature regulation between adjacent temperature probes, significantly improving the temperature uniformity of the annealing machine.

[0030] Furthermore, the present invention adjusts the power of the heating components in some areas according to the first temperature distribution, thereby further improving the temperature uniformity of the annealing machine. Attached Figure Description

[0031] Figure 1 A flowchart of a method for improving the temperature uniformity of an annealing machine according to an embodiment of the present invention;

[0032] Figure 2 This is a schematic diagram of the structure of an annealing machine provided in an embodiment of the present invention;

[0033] Figure 3 for Figure 2 A top view of the annealing machine;

[0034] Figure 4 for Figure 2 A schematic diagram of the structure of the base of the annealing machine;

[0035] Figure 5 for Figure 2 A schematic diagram of the heating assembly in the annealing machine;

[0036] Figure 6 This is a schematic diagram illustrating the adjustment of the orientation of the heating component in a method for improving the temperature uniformity of an annealing machine according to an embodiment of the present invention.

[0037] Figure 7 This is a schematic diagram of the first temperature distribution in a method for improving the temperature uniformity of an annealing machine according to an embodiment of the present invention.

[0038] Figure 8 This is a schematic diagram of the second temperature distribution in a method for improving the temperature uniformity of an annealing machine according to an embodiment of the present invention.

[0039] Figure 9 This is a schematic diagram showing the temperature distribution of the annealing machine after adjusting the orientation of the heating components in a method for improving the temperature uniformity of an annealing machine according to an embodiment of the present invention.

[0040] The reference numerals in the attached figures are as follows:

[0041] 1-Annealing machine; 10-Base; 11-Heating assembly; 111-Bulb; 111a-Straight filament; 111b-Helical filament; 112-Lamp cover; 20-Wafer stage; 30-Temperature probe; 2-Wafer;

[0042] X1 - Central circular area; X2~X7 - Surrounding annular area; T1~T7 - Temperature probes. Detailed Implementation

[0043] To make the objectives, advantages, and features of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that the drawings are all in a very simplified form and are not drawn to scale, and are only used to facilitate and clarify the explanation of the embodiments of this invention. Furthermore, the structures shown in the drawings are often part of the actual structures. In particular, different figures may emphasize different aspects and may sometimes use different scales.

[0044] As used in this invention, the singular forms “a,” “an,” and “the” include plural objects; the term “or” is generally used to mean “and / or”; the term “a number” is generally used to mean “at least one”; and the term “at least two” is generally used to mean “two or more”. Furthermore, the terms “first,” “second,” and “third” are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as “first,” “second,” or “third” may explicitly or implicitly include one or at least two of that feature. “One end” and “the other end,” as well as “proximal end” and “distal end,” generally refer to two corresponding parts, including not only endpoints. The terms “installed,” “connected,” and “joined” should be interpreted broadly, for example, as a fixed connection, a detachable connection, or an integral part; a mechanical connection or an electrical connection; a direct connection or an indirect connection through an intermediate medium; or a connection within two elements or an interaction between two elements. Furthermore, as used in this invention, the phrase "one element is disposed on another element" generally only indicates that there is a connection, coupling, cooperation, or transmission relationship between the two elements, and the connection, coupling, cooperation, or transmission between the two elements can be direct or indirect through an intermediate element. It should not be construed as indicating or implying a spatial positional relationship between the two elements, i.e., one element can be located arbitrarily inside, outside, above, below, or to one side of the other element, unless otherwise explicitly stated. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0045] Figure 1 This is a flowchart of a method for improving the temperature uniformity of an annealing machine according to an embodiment of the present invention.

[0046] See Figure 1 The method for improving the temperature uniformity of the annealing machine described in this embodiment includes:

[0047] Step S01: Provide an annealing machine, the annealing machine including a base and a wafer carrier stage disposed on the base, the base being provided with a plurality of heating components, the temperature of the area facing the heating components being higher than the temperature of other areas around the heating components;

[0048] Step S02: Place a wafer on the wafer carrier, measure and obtain the first temperature distribution on the wafer, and determine whether the temperature uniformity of the annealing machine is qualified.

[0049] Step S03: If the temperature uniformity of the annealing machine is not up to standard, adjust the orientation of the heating component to improve the temperature uniformity of the annealing machine.

[0050] Figures 2 to 5 This is a schematic diagram of the annealing machine described in this embodiment. Figure 6 This is a schematic diagram illustrating some steps in the method for improving the temperature uniformity of the annealing machine described in this embodiment. The following is in conjunction with... Figures 2 to 6 This embodiment describes in detail the method for improving the temperature uniformity of an annealing machine.

[0051] First, refer to Figures 2 to 5 In step S01, an annealing machine 1 is provided. The annealing machine 1 includes a base 10 and a wafer carrier stage 20 disposed on the base. A plurality of heating components 11 are disposed in the base. The temperature of the area facing the heating component 11 is higher than the temperature of other areas around the heating component 11.

[0052] In this embodiment, the annealing machine 1 is a back-illuminated annealing machine. In other embodiments of the present invention, the annealing machine may also be other types of annealing machines, such as a front-illuminated annealing machine. The present invention does not limit this.

[0053] See Figure 2 and Figure 3 In this embodiment, the annealing machine 1 further includes a plurality of temperature probes 30, which are disposed above the wafer carrier stage 20 and are not located at the center of the wafer carrier stage 20 (i.e., Figure 3 The distances between points A and B in the figure are different, so as to measure the temperature probe 30 (i.e. Figure 3 The temperature probes 30 are located within the central circular region X1 or the surrounding annular regions X2 to X7 of the wafer carrier stage 20. In this embodiment, the temperature probes 30 are arranged in a straight line. In other embodiments of the present invention, the temperature probes 30 may be arranged in a curved line or randomly distributed above the wafer carrier stage 20. The specific distribution of the temperature probes 30 can also be set according to actual needs, as long as the condition that "different temperature probes are located relative to the center of the wafer carrier stage (i.e., the temperature probes are located within the central circular region X1 or the surrounding annular region X2 to X7)" is met. Figure 3The condition that "the distances between points A and B are different" is sufficient; this invention does not impose any restrictions on this.

[0054] Figure 4 for Figure 2 A schematic diagram of the structure of the base of the annealing machine. Figure 5 for Figure 2 A schematic diagram of the heating assembly in the annealing machine. (See attached diagram.) Figure 4 and Figure 5 The multiple heating components 11 inside the base 10 are arranged in a honeycomb pattern. Each heating component 11 includes a bulb 111 and a lampshade 112 surrounding the bulb 111. The lampshade 112 is cylindrical, and the light emitted by the bulb 111 is emitted from the top of the lampshade 112.

[0055] Continue reading Figure 5 The bulb 111 includes a straight filament 111a and a spiral filament 111b. The extension direction of the straight filament 111a and the spiral filament 111b is the same as the axial direction of the lamp cover 112. One end of the straight filament 111a and the spiral filament 111b are connected, and the other end is inserted into the base 10 and electrically connected to the internal circuit (not shown in the figure) of the base 10. The direction of the bulb 111 near the straight filament 111a is the orientation of the bulb 111.

[0056] It should be noted that the lampshade 112 is fitted around the bulb 111 and can reflect the light emitted by the bulb 111 in all directions, so that all the light emitted by the bulb 111 is emitted from the top of the lampshade 112, and most of the light is concentrated in the area near the straight filament 111a. This enables the bulb to achieve the heating function and makes the temperature of the area facing the bulb 111 higher than the temperature of other areas around the bulb 111.

[0057] Continue reading Figure 2 In step S02, a wafer 2 is placed on the wafer carrier stage 20, the first temperature distribution on the wafer 2 is measured and obtained, and it is determined whether the temperature uniformity of the annealing machine stage 1 is qualified.

[0058] In this embodiment, the first temperature distribution on wafer 2 is obtained by measuring sheet resistance using the Line method. In other embodiments of the present invention, the first temperature distribution on wafer 2 can also be obtained by other methods, such as measuring sheet resistance using the Map method. The present invention does not limit this.

[0059] Then refer to Figure 3 , Figure 4 and Figure 6 If the temperature uniformity of the annealing machine 1 is not up to standard, then the orientation of the heating component 11 is adjusted to improve the temperature uniformity of the annealing machine 1.

[0060] For example, if the temperature uniformity of the annealing machine is not up to standard, the process of adjusting the orientation of the heating component includes: if the temperature uniformity of the annealing machine is not up to standard, adjusting the power of the heating component 11; measuring and obtaining the second temperature distribution on the wafer 2 again, and determining again whether the temperature uniformity of the annealing machine 1 is up to standard; if the temperature uniformity of the annealing machine 1 is still not up to standard, adjusting the orientation of the heating component 11.

[0061] In this embodiment, the process of adjusting the power of the heating component 11 includes: analyzing the first temperature distribution and setting the area with the highest and / or lowest temperature as the first area to be adjusted; and adjusting the power of all heating components 11 in the first area to be adjusted to improve the temperature uniformity of the annealing machine 1.

[0062] Combination Figure 3 and Figure 4 It is understood that the first area to be adjusted may include one, two, or more of the central circular area X1 and the surrounding annular areas X2 to X7. Therefore, when adjusting the power of the heating component 11, the average temperature of the annealing machine can be obtained based on the first temperature distribution. The power of all heating components 11 in areas with temperatures higher than the average temperature can be reduced, and the power of all heating components 11 in areas with temperatures lower than the average temperature can be increased, thereby achieving temperature uniformity adjustment of the annealing machine 1. In other embodiments of the present invention, the temperature uniformity adjustment of the annealing machine 1 can also be achieved by adjusting other parameter settings of the annealing machine to reduce the temperature difference between areas corresponding to different temperature probes.

[0063] In this embodiment, the process of adjusting the orientation of the heating component 11 includes: analyzing the second temperature distribution, obtaining the temperature difference between the temperatures measured by all adjacent temperature probes 30, and setting the area corresponding to the two adjacent temperature probes 30 with the largest temperature difference as the second adjustment area; and adjusting the orientation of all heating components 11 in the second adjustment area to improve the temperature uniformity of the annealing machine 1.

[0064] The following uses the central circular region X1 and the surrounding annular region X2 as an example to illustrate the process of adjusting the orientation of all heating components 11 within the second region to be adjusted. Figure 6 for Figure 4 A partially enlarged schematic diagram, and Figure 6At least including the central circular region X1 and the surrounding annular region X2): First, the two adjacent temperature probes 30 with the largest temperature difference are defined as the first temperature probe (i.e., temperature probe T1) and the second temperature probe (i.e., temperature probe T2), respectively. All heating components 11 in the region corresponding to the first temperature probe T1 (i.e., the central circular region X1) are defined as the first heating component 11a, and all heating components 11 in the region corresponding to the second temperature probe T2 (i.e., the surrounding annular region X2) are defined as the second heating component 11b; and the orientation of the first heating component 11a and the second heating component 11b is adjusted ( Figure 6 The arrows in the diagram indicate the orientation of the heating components, so that all the first heating components 11a face the area corresponding to the second temperature probe T2 (i.e., the surrounding annular area X2), and all the second heating components 11b face the area corresponding to the first temperature probe T1 (i.e., the central circular area X1).

[0065] It should be noted that, since the heating component 11 described in this embodiment is inserted into the base 10 through the straight filament 111a and the spiral filament 111b, the orientation of the heating component 11 can only be adjusted by rotating it 180°. In other embodiments of the present invention, the heating component 11 can be adjusted to be a rotatable heating component, thereby achieving flexible adjustment of the orientation of the heating component 11. The specific structure of the rotatable heating component can be set by combining conventional mechanical structure knowledge, which will not be elaborated in this invention.

[0066] contrast Figure 7 and Figure 8 It can be seen that before adjusting the power of the heating component, the temperature in the area corresponding to temperature probes T1 to T3 was too high; after adjusting the power of the heating component in the area corresponding to temperature probes T1 to T3, the temperature in the area corresponding to temperature probes T1 to T3 decreased relatively. (Comparison) Figure 8 and Figure 9 It can be seen that before adjusting the orientation of the heating components, the temperature change in the area between temperature probes T1 and T2 was drastic and the temperature difference was large; after adjusting the orientation of the heating components in the corresponding areas of temperature probes T1 and T2, the temperature change in the area between temperature probes T1 and T2 was smaller and the temperature difference decreased. Therefore, the method for improving the temperature uniformity of the annealing machine described in this embodiment not only improves the temperature uniformity of the annealing machine by adjusting the power of the heating components in some areas, but also further improves the temperature uniformity of the annealing machine by adjusting the orientation of the heating components in two adjacent areas.

[0067] In summary, this invention provides a method for improving the temperature uniformity of an annealing machine. The annealing machine includes a base and a wafer carrier stage disposed on the base. Multiple heating elements are disposed within the base. The temperature of the area oriented towards the heating elements is higher than the temperature of other areas surrounding the heating elements. A wafer is placed on the wafer carrier stage, and a first temperature distribution on the wafer is measured to determine whether the temperature uniformity of the annealing machine is acceptable. If the temperature uniformity of the annealing machine is unacceptable, the orientation of the heating elements is adjusted to improve the temperature uniformity of the annealing machine. This invention, by adjusting the orientation of the heating elements, achieves temperature regulation between adjacent temperature probes, significantly improving the temperature uniformity of the annealing machine.

[0068] Furthermore, the present invention adjusts the power of the heating components in some areas according to the first temperature distribution, thereby further improving the temperature uniformity of the annealing machine.

[0069] The above are merely preferred embodiments of the present invention and do not constitute any limitation on the present invention. Any equivalent substitutions or modifications made by those skilled in the art to the technical solutions and content disclosed in the present invention without departing from the scope of the present invention shall be deemed to have remained within the protection scope of the present invention.

Claims

1. A method for improving the temperature uniformity of an annealing machine, characterized in that, include: An annealing machine is provided, the annealing machine includes a base and a wafer carrier stage disposed on the base, the base is provided with a plurality of heating components, the plurality of heating components in the base are arranged in a honeycomb pattern, and the temperature of the area facing the heating components is higher than the temperature of other areas around the heating components; A wafer is placed on the wafer carrier stage, the first temperature distribution on the wafer is measured and obtained, and it is determined whether the temperature uniformity of the annealing machine is qualified. If the temperature uniformity of the annealing machine is not up to standard, the orientation of the heating component shall be adjusted to improve the temperature uniformity of the annealing machine. The annealing machine also includes multiple temperature probes, which are positioned above the wafer carrier stage. The distance between each temperature probe and the center of the wafer carrier stage is different, so as to measure the temperature of the central circular area or the surrounding annular area where the temperature probe is located. If the temperature uniformity of the annealing machine is unsatisfactory, the process of adjusting the orientation of the heating assembly includes: If the temperature uniformity of the annealing machine is not up to standard, adjust the power of the heating component. The second temperature distribution on the wafer is measured again, and the temperature uniformity of the annealing machine is judged again. If the temperature uniformity of the annealing machine is still not up to standard, then adjust the orientation of the heating assembly. The process of adjusting the orientation of the heating component includes: Analyze the second temperature distribution, obtain the temperature difference between the temperatures measured by all adjacent temperature probes, and set the region corresponding to the two adjacent temperature probes with the largest temperature difference as the second region to be adjusted; and, Adjust the orientation of all heating components in the second area to be adjusted to improve the temperature uniformity of the annealing machine.

2. The method for improving the temperature uniformity of an annealing machine as described in claim 1, characterized in that, The process of adjusting the power of the heating component includes: Analyzing the first temperature distribution, the region with the highest and / or lowest temperature is designated as the first region to be adjusted; and, Adjust the power of all heating components in the first area to be adjusted to improve the temperature uniformity of the annealing machine.

3. The method for improving the temperature uniformity of an annealing machine as described in claim 1, characterized in that, The process of adjusting the orientation of all heating components within the second area to be adjusted includes: The two adjacent temperature probes with the largest temperature difference are defined as the first temperature probe and the second temperature probe, respectively. All heating components within the region corresponding to the first temperature probe are defined as the first heating component, and all heating components within the region corresponding to the second temperature probe are defined as the second heating component; and... Adjust the orientation of the first heating component and the second heating component so that all the first heating components face the area corresponding to the second temperature probe, and all the second heating components face the area corresponding to the first temperature probe.

4. The method for improving the temperature uniformity of an annealing machine as described in claim 1, characterized in that, The heating assembly includes a bulb and a lampshade surrounding the bulb. The lampshade is cylindrical, and the light emitted by the bulb exits from the top of the lampshade.

5. The method for improving the temperature uniformity of an annealing machine as described in claim 4, characterized in that, The bulb includes a straight filament and a spiral filament. The extension directions of the straight filament and the spiral filament are the same as the axial direction of the lampshade. One end of the straight filament and the spiral filament are connected, and the other end is inserted into the base and electrically connected to the internal circuit of the base. The direction of the bulb closer to the straight filament is the orientation of the bulb.

6. The method for improving the temperature uniformity of an annealing machine as described in claim 1, characterized in that, The first and second temperature distributions on the wafer are obtained by measuring the sheet resistance.

7. The method for improving the temperature uniformity of an annealing machine as described in claim 1, characterized in that, The annealing machine includes a back-illuminated annealing machine and a front-illuminated annealing machine.

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