Thin film deposition wafer, preparation method thereof and method for predicting surface appearance of thin film deposition wafer

Abstract

The invention relates to a method for predicting the surface topography of a thin film deposition wafer, a method for preparing the thin film deposition wafer and the thin film deposition wafer. The method for predicting the surface topography of the thin film deposition wafer comprises the step of obtaining the predicted surface topography of a prepared wafer after the thin film deposition process according to the surface topography height of the prepared wafer and the surface topography height difference corresponding to the thin film deposition process. By using the method for predicting the surface topography of the thin film deposition wafer, the thin film deposition wafer of which the surface topography meets the requirement can be obtained, the product yield is improved, and the waste of wafer materials is reduced.

Description

Technical Field

[0001] The present disclosure relates to the field of semiconductor manufacturing technology, and in particular, to a method for predicting the surface morphology of a thin film deposition wafer, a method for preparing a thin film deposition wafer, and a thin film deposition wafer. Background Art

[0002] In the field of semiconductor wafer manufacturing, thin film deposition process is a technology for forming thin films on substrate wafers. Common thin film deposition processes include epitaxial growth and back-sealing processes. Epitaxial growth is the process of growing single-crystal silicon thin films on substrate wafers, which is usually used to manufacture integrated circuits and microelectronic devices. Back-sealing refers to the formation of a layer of film on the back of the substrate wafer, which can protect the substrate wafer from contamination and improve the reliability and stability of the device. In addition, by back-sealing the substrate wafer before epitaxial growth, self-doping during the epitaxial process can be avoided.

[0003] The back-sealing and epitaxial processes are usually carried out at high temperatures, and the wafer products that are deposited to form the back-sealing layer or epitaxial layer need to be cooled from high temperature to room temperature after the process is completed. However, since the thermal expansion coefficient of the back-sealing layer or epitaxial layer is different from that of the substrate wafer, the resulting wafer products will deform to a certain extent during the cooling process. The detection of the surface morphology of the wafer product is carried out after the back-sealing or epitaxial process is completed. At this time, even if deformation problems are detected in the wafer product, it is difficult or even impossible to adjust and change it, so that the wafer product may face scrapping due to the surface morphology failing to meet customer specifications, which leads to a decrease in product yield and waste of wafer materials. Summary of the invention

[0004] This section provides a general summary of the disclosure, and is not a comprehensive disclosure of its full scope or all of its features.

[0005] The purpose of the present disclosure is to provide a method for predicting the surface morphology of a thin film deposition wafer and a method for preparing a thin film deposition wafer, which can be helpful in obtaining a thin film deposition wafer whose surface morphology meets the requirements.

[0006] The purpose of the present disclosure is to provide a method for predicting the surface morphology of a thin film deposition wafer and a method for preparing a thin film deposition wafer, which can improve the yield of the thin film deposition wafer.

[0007] The object of the present disclosure is to provide a method for predicting the surface morphology of a thin film deposition wafer and a method for preparing a thin film deposition wafer, which can reduce the waste of wafer materials.

[0008] In order to achieve the above-mentioned purpose, according to the first aspect of the present disclosure, a method for predicting the surface morphology of a thin film deposition wafer is provided, comprising: obtaining the predicted surface morphology of the prepared wafer after the thin film deposition process based on the surface morphology height of the prepared wafer and the surface morphology height difference corresponding to the thin film deposition process.

[0009] In some embodiments of the above method for predicting the surface morphology of a thin film deposited wafer, the surface morphology height difference corresponding to the thin film deposition process can be obtained based on the deformation of the prepared wafer after the thin film deposition process characterized by curve fitting.

[0010] In some embodiments of the above-mentioned method for predicting the surface morphology of a thin film deposited wafer, the surface morphology height difference corresponding to the thin film deposition process can be obtained based on the deformation characterized by the curvature of a circle fit, the curvature of a spherical fit, or the constant term of a binomial parabola.

[0011] In some embodiments of the above method for predicting the surface morphology of a thin film deposition wafer, the thin film deposition process may be at least one of a wafer front side thin film deposition process and a wafer back side thin film deposition process.

[0012] In some embodiments of the above method for predicting the surface topography of a thin film deposition wafer, the surface topography height of the prepared wafer can be measured by a topography measuring instrument, and the measurement is sampled along the radial direction of the prepared wafer.

[0013] According to a second aspect of the present disclosure, a method for preparing a thin film deposition wafer is provided, comprising: before performing a thin film deposition process on a prepared wafer, executing the method for predicting the surface morphology of a thin film deposition wafer according to the first aspect of the present disclosure.

[0014] In some embodiments, the above method for preparing a thin film deposition wafer may include: grading and screening the prepared wafers according to the prediction results.

[0015] In some embodiments, the above method for preparing a thin film deposition wafer may include: adjusting parameters of the thin film deposition process according to the prediction result to compensate for the predicted surface morphology of the prepared wafer with respect to the growth surface morphology.

[0016] In some embodiments, adjusting a parameter of the thin film deposition process may include adjusting a growth parameter of the thin film deposition process.

[0017] According to a third aspect of the present disclosure, a thin film deposition wafer is provided, which is obtained by using the method for preparing a thin film deposition wafer according to the second aspect of the present disclosure, wherein the thin film deposition wafer is an epitaxial wafer and a warpage value of the thin film deposition wafer is less than 6500nm.

[0018] According to the above technical solution, the surface morphology of the thin film deposition wafer obtained after the thin film deposition process can be predicted in advance without actually subjecting the wafer to the thin film deposition process, thereby facilitating the prejudgment of whether the predicted surface morphology of the thin film deposition wafer can meet the corresponding requirements. Based on this, it is possible to screen the wafers, selectively subject the wafers whose predicted results meet the requirements to the thin film deposition process, and subject the wafers whose predicted results do not meet the requirements to other treatments such as rework, thereby helping to control the surface morphology of the thin film deposition wafer actually obtained within the qualified range, improve the production yield, and reduce wafer waste. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The features and advantages of the embodiments of the present disclosure will become more easily understood through the following description with reference to the accompanying drawings. The drawings are not drawn to scale and some features may be enlarged or reduced to show details of specific components. In the drawings: Figure 1 A schematic diagram of the surface morphology of the substrate and the film layer at high temperature is shown.

[0020] Figure 2 A schematic diagram showing the surface morphology of the substrate and the film layer after returning to room temperature.

[0021] Figure 3 The figure shows the surface morphology height distribution of the test wafer in the diameter direction before the back-sealing process.

[0022] Figure 4 The figure shows the surface morphology height distribution of the test wafer along the diameter direction after the back-sealing process.

[0023] Figure 5 The figure shows the distribution diagram of the surface morphology height change along the diameter direction of the test wafer before and after the back-sealing process.

[0024] Figure 6 The figure shows the result of circular fitting of the deformation of the wafer during the back-sealing process.

[0025] Figure 7 A schematic diagram showing the diameters selected on the wafer for circle fitting curvature deviation analysis.

[0026] Figure 8 The results of binomial parabola fitting for the deformation of the wafer during the back-sealing process are shown.

[0027] Fig. 9 The original surface morphology of the wafer before the thin film deposition process is shown.

[0028] Fig.10The predicted surface morphology of a wafer after a thin film deposition process is shown according to the method for predicting the surface morphology of a thin film deposition wafer according to an embodiment of the present disclosure.

[0029] Fig.11 The actual surface morphology of the wafer after the thin film deposition process is shown.

[0030] Fig.12 A schematic diagram showing a method for predicting the surface morphology of a thin film deposition wafer according to an embodiment of the present disclosure is shown.

[0031] Fig.13 A schematic diagram comparing the warpage (Warp value) of a wafer obtained according to the related art and a wafer obtained according to the method for preparing a thin film deposition wafer according to an embodiment of the present disclosure is shown. DETAILED DESCRIPTION

[0032] The present disclosure is described in detail below with reference to the accompanying drawings by means of exemplary embodiments. It should be noted that the following detailed description of the present disclosure is only for illustrative purposes and is by no means a limitation of the present disclosure.

[0033] As mentioned above, after cooling from high temperature to room temperature, the substrate wafer that has undergone the back-sealing process or the substrate wafer that has undergone the epitaxial growth process may deform to a certain extent due to the difference in thermal expansion coefficient between the film layer and the substrate wafer. This deformation causes the surface morphology of the substrate wafer to change compared to its original surface morphology, such as Figure 1 and Figure 2 As shown, the substrate wafer B is, for example, bent or warped as a whole toward the side where the film layer A is located.

[0034] In view of the above phenomenon, the inventors analyzed the changes in the surface morphology of the wafer caused by the back-sealing process or the epitaxial process. Taking the back-sealing process as an example, the inventors analyzed the changes in the surface morphology of the same type of wafers after the same type of back-sealing process. Specifically, 5 test wafers were selected and subjected to the same type of back-sealing process. Figures 3 to 5 In FIG. 1 , data curves corresponding to the test wafers are indicated by S1 to S5 . The selected test wafers are wafers with the same specifications that are cut continuously from the same crystal rod and can be regarded as having the same physical and chemical properties.

[0035] First, select points on the surface of the test wafer that are perpendicular to the notch direction as sampling points, and obtain the height data of each sampling point before the back-sealing process and the height data of each sampling point after the back-sealing process. It should be understood that the height referred to in this article refers to the distance of a point on the wafer surface relative to a reference plane in the thickness direction of the wafer, and the reference plane is a plane perpendicular to the thickness direction.

[0036] like Figure 3 and Figure 4 As shown, height distribution curves of each sampling point of the test wafer before and after the back-sealing process are drawn according to the acquired height data, wherein the abscissa represents the position of the sampling point on the selected diameter, and the ordinate represents the height of the sampling point.

[0037] Subsequently, according to Figure 3 and Figure 4 The height distribution curve shown is a distribution curve representing the height change of the test wafer at the sampling point before and after the back-sealing process, such as Figure 5 As shown in Figure 1, the curve reflects the deformation of the aforementioned type of test wafer after the aforementioned back-sealing process. The results show that the deformation of the same type of wafer after the same type of back-sealing process is the same. By analogy, the deformation caused by the same type of thin film deposition process on the same type of wafer should be the same.

[0038] It should be noted that the same type of wafers referred to herein refers to wafers with the same physical and chemical properties, such as wafers of the same batch cut continuously from the same crystal rod, which are commonly referred to as "sister wafers" in the industry. The same type of thin film deposition process refers to a thin film deposition process based on the same thin film deposition principle, using the same reaction equipment and the same process parameters.

[0039] Based on the above findings, the present disclosure attempts to predict the morphology of the prepared wafer after the thin film deposition process based on the morphology of the prepared wafer before the thin film deposition process. Specifically, referring to Fig.12 According to an embodiment of the present disclosure, a method for predicting the surface morphology of a thin film deposition wafer is provided, comprising step S100: obtaining a predicted surface morphology of the prepared wafer after the thin film deposition process according to the surface morphology height of the prepared wafer and the surface morphology height difference corresponding to the thin film deposition process.

[0040] Specifically, the predicted surface morphology of the prepared wafer after the thin film deposition process can be obtained by superimposing the surface morphology height of the prepared wafer with the surface morphology height difference corresponding to the thin film deposition process.

[0041] Here, the prepared wafer refers to a wafer that is prepared for a thin film deposition process but has not yet undergone the thin film deposition process. The thin film deposition wafer refers to a wafer that has undergone a thin film deposition process and has formed a film layer on the surface. It is understandable that in this prediction method, the prepared wafer does not actually undergo a thin film deposition process, and thus a thin film deposition wafer is not actually obtained.

[0042] In the present disclosure, the surface topography height of the prepared wafer refers to the height of each point on the surface of the prepared wafer. It is understandable that the height difference of each point on the surface of the prepared wafer reflects the ups and downs of the surface of the prepared wafer, that is, characterizes the surface topography of the prepared wafer. Here, the "surface" of the prepared wafer can be the front side or the back side.

[0043] The surface morphology height difference corresponding to the thin film deposition process refers to the difference between the surface morphology height of the prepared wafer deformed by the thin film deposition process and the surface morphology height of the prepared wafer that has not undergone the thin film deposition process, that is, the change in the surface morphology of the prepared wafer brought about by the thin film deposition process.

[0044] like Figures 9 to 11 As shown, the method for predicting the surface morphology of a thin film deposition wafer according to an embodiment of the present disclosure predicts the surface morphology of the prepared wafer after the thin film deposition process (see Fig.10 ) and the actual surface morphology of the prepared wafer after the film deposition process (see Fig.11 ). This shows that the above method can reliably predict the surface morphology of the thin film deposition wafer formed by the prepared wafer after the thin film deposition process.

[0045] Through the above prediction method, it is possible to know in advance the surface morphology of the thin film deposition wafer that will be formed after the thin film deposition process is performed on the prepared wafer without actually performing the thin film deposition process on the prepared wafer. On this basis, it is possible to prejudge whether the predicted surface morphology can meet the corresponding standards. For example, it is convenient to screen out those prepared wafers whose surface morphology has been predicted to meet the standards from the prepared wafers to implement the thin film deposition process, thereby advantageously avoiding the situation where the prepared wafer has undergone the thin film deposition process but the surface morphology of the obtained thin film deposition wafer is found to be not up to standard, and then it is helpful to control the surface morphology of the actually obtained thin film deposition wafer within the qualified range and improve the production yield. In addition, the above method is also convenient for screening out the prepared wafers whose predicted surface morphology does not meet the standards, and it can be selected to be reworked or otherwise processed, thereby reducing the waste of the prepared wafers.

[0046] In some embodiments of the above method for predicting the surface morphology of a thin film deposition wafer, the thin film deposition process may be at least one of a wafer front side thin film deposition process and a wafer back side thin film deposition process.

[0047] Specifically, the wafer front thin film deposition process refers to thin film deposition on the front surface of the prepared wafer, such as an epitaxial process. The wafer back thin film deposition process refers to thin film deposition on the back surface of the prepared wafer, such as a back sealing process.

[0048] Exemplarily, when the prepared wafer is the original wafer and the thin film deposition process is a back-sealing process, the thin film deposition wafer is a back-sealing wafer, and the method for predicting the surface morphology of the back-sealing wafer includes: obtaining the predicted surface morphology of the original wafer after the back-sealing process based on the surface morphology height of the original wafer and the surface morphology height difference corresponding to the back-sealing process.

[0049] Exemplarily, when the prepared wafer is an original wafer and the thin film deposition process is an epitaxial process, the thin film deposition wafer is an epitaxial wafer, and the method for predicting the surface morphology of the epitaxial wafer includes: obtaining the predicted surface morphology of the original wafer after the epitaxial process according to the surface morphology height of the original wafer and the surface morphology height difference corresponding to the epitaxial process. It should be noted here that the surface morphology height difference corresponding to the epitaxial process refers to the surface morphology height difference caused by this type of epitaxial process to this type of original wafer.

[0050] Exemplarily, in the case where the prepared wafer is a back-sealed wafer and the thin film deposition process is an epitaxial process, the thin film deposition wafer is an epitaxial wafer with a back seal, and the method for predicting the surface morphology of the epitaxial wafer with a back seal includes: obtaining the predicted surface morphology of the back-sealed wafer after the epitaxial process according to the surface morphology height of the back-sealed wafer and the surface morphology height difference corresponding to the epitaxial process. It should be noted that, unlike the case where the prepared wafer is the original wafer, here, the surface morphology height difference corresponding to the epitaxial process refers to the surface morphology height difference caused by this type of epitaxial process to this type of back-sealed wafer.

[0051] It is understandable that the wafer front side thin film deposition process and the wafer back side thin film deposition process may adopt, for example, chemical vapor deposition (CVD) technology, physical vapor deposition (PVD) technology, atomic layer deposition (ALD) technology, etc., but are not limited thereto.

[0052] In some embodiments of the above method for predicting the surface topography of a thin film deposition wafer, the surface topography height of the prepared wafer can be measured using a topography measuring instrument, and the measurement can be sampled along the radius of the prepared wafer. For example, the measurement can select sampling points along the diameter of the prepared wafer, for example, along a diameter perpendicular to the notch direction.

[0053] In order to quantify the deformation of the prepared wafer after the thin film deposition process, in some embodiments, the deformation of the prepared wafer after the thin film deposition process may be fitted, for example, the fitting method may be circle fitting, spherical fitting or binomial parabola fitting.

[0054] In the case of circular fitting, the height change value of a point on a diameter of the surface of the same type of wafer as the prepared wafer before and after the thin film deposition process can be used as the original data for circular fitting. The fitting result is as follows: Figure 6As shown in the figure, the original data is represented by the black solid line and the fitting curve is represented by the white dotted line. The results show that the fitting model obtained by circle fitting has a high degree of fitting for the original data.

[0055] The circle fitting result shows that the deformation of the wafer after the thin film deposition process can be characterized by the arc corresponding to the fitting result. For example, the deformation can be characterized by the identification features of the arc, such as the curvature k (or the radius of curvature R) or the bow height length (Bow) corresponding to the arc.

[0056] Furthermore, the deformation of any point on the surface of the wafer due to the thin film deposition process can be represented by an arc or a substantially arc, so the height change value of the point on the surface of the wafer can also be used for spherical fitting. Figure 7 As shown in the figure, 72 diameters (indicated by P in the figure) were selected on the surface of the wafer for circle fitting and circle fitting curvature deviation analysis. The results show that the deviation of the curvature obtained by circle fitting with different diameters of the same wafer is very small, specifically around 0.1%. This shows that the deformation of the wafer after the thin film deposition process can be characterized by the spherical surface obtained by spherical surface fitting, for example, the identification features of the spherical surface such as curvature k (or curvature radius R) can be used to characterize it.

[0057] also, Figure 8 The fitting result obtained by binomial parabola fitting is shown, wherein the original data is represented by a lighter solid line C1 and the fitting curve is represented by a darker dot-dash line C2. Figure 8 It shows that the fitting result has a high degree of fit to the original data. Therefore, the binomial parabola fitting result can also be reliably used to characterize the deformation of the wafer after the thin film deposition process. For example, the deformation of the wafer after the thin film deposition process can be characterized by the constant term of the binomial parabola fitting.

[0058] Based on this, in some embodiments, the surface morphology height difference corresponding to the thin film deposition process can be obtained according to the deformation of the prepared wafer after the thin film deposition process characterized by a curve fitting method.

[0059] For example, the height difference of the surface topography corresponding to the thin film deposition process can be obtained according to the deformation characterized by the curvature using circle fitting.

[0060] In this case, for example, the following formula (1) can be used to obtain the predicted surface topography height of the prepared wafer after the thin film deposition process: (1) in, The coordinates of the sampling points on the surface of the prepared wafer are expressed in the form of polar coordinates. is the original height of the sampling point, is the predicted height of the sampling point after thin film deposition on the prepared wafer. is the curvature of the arc obtained by circle fitting, represents the radius of the prepared wafer. k , L , ρ The collectively composed terms may represent or measure deformation that may occur to the prepared wafer after undergoing the thin film deposition process. Indicates the thickness of the film layer that will be formed after the thin film deposition process. When sampling on the front side of the prepared wafer, in the case of the wafer front side thin film deposition process, is the thickness of the film layer formed on the front side of the prepared wafer. In the case of a thin film deposition process on the back side of the wafer, is 0.

[0061] In formula (1), the surface morphology height difference corresponding to the thin film deposition process is specifically determined by the term considering the fitting result and the term representing the film thickness The sum represents .

[0062] In some embodiments, the surface topography height difference corresponding to the thin film deposition process can also be obtained based on the deformation characterized by the curvature of the spherical fitting or the constant term of the binomial parabola. Therefore, it should be understood that the calculation method of the predicted surface height of the prepared wafer after the thin film deposition process is not limited to this, and a suitable calculation method can also be determined based on the fitting results of other fitting methods.

[0063] According to another aspect of the present disclosure, a method for preparing a thin film deposition wafer is provided, comprising: before performing a thin film deposition process on a prepared wafer, executing the method for predicting the surface morphology of a thin film deposition wafer according to an embodiment of the present disclosure.

[0064] It should be understood that the prediction result refers to the predicted surface morphology of the prepared wafer after the thin film deposition process obtained according to the method for preparing a thin film deposition wafer according to the embodiment of the present disclosure.

[0065] By predicting in advance the surface morphology of the thin film deposition wafer that will be obtained after the prepared wafer undergoes the thin film deposition process before the thin film deposition process is performed, it is convenient to guide the subsequent thin film deposition process operation according to the prediction result.

[0066] Exemplarily, the thin film deposition process may include a front thin film deposition process and / or a wafer back thin film deposition process. It should be understood that in the method for preparing a thin film deposition wafer according to an embodiment of the present disclosure, before performing any thin film deposition process, the method for predicting the surface morphology of a thin film deposition wafer according to an embodiment of the present disclosure is first performed.

[0067] For example, in the case of performing a back-sealing process and an epitaxial process on the original wafer, such as the case of performing the back-sealing process first and then the epitaxial process, before performing the back-sealing process, predict the first predicted surface morphology of the original wafer after the back-sealing process. When it is determined that the first predicted surface morphology of the original wafer can meet the standard, perform the back-sealing process on the original wafer to obtain a back-sealed wafer. Subsequently, before performing the epitaxial process on the back-sealed wafer, predict the second predicted surface morphology of the back-sealed wafer after the epitaxial process. When it is determined that the second predicted surface morphology of the back-sealed wafer can meet the standard, perform the epitaxial process on the back-sealed wafer to obtain an epitaxial wafer with a back seal.

[0068] In some embodiments, the method of preparing a thin film deposition wafer may include: grading and screening the prepared wafer according to the prediction result.

[0069] Specifically, after obtaining the predicted surface morphology of the prepared wafer after the thin film deposition process, the predicted surface morphology can be evaluated according to the standards corresponding to the parameters used to characterize the wafer surface morphology (referred to as surface morphology parameters) to grade the prepared wafer.

[0070] The surface topography parameters may include but are not limited to SFQR, ESFQR, SBIR, GBIR, Warp, Bow, Nanotopography, etc. These surface topography parameters may be determined based on the height of a point on the surface of the prepared wafer, wherein the height of a point on the surface of the prepared wafer may be calculated using formula (1).

[0071] For example, the prepared wafers can be graded and screened according to the parameter values ​​of the predicted surface morphology and their corresponding thresholds. Taking Warp as an example, when the Warp value of the predicted surface morphology of the prepared wafer does not exceed the Warp threshold, the prepared wafer is judged as a "qualified" prepared wafer, otherwise, the prepared wafer is judged as an "unqualified" prepared wafer.

[0072] In this case, the prepared wafers can be screened according to the grading results of the prepared wafers. For example, "qualified" prepared wafers can be screened out for the preparation of thin film deposition wafers, and "unqualified" prepared wafers can be selected for rework or other treatment. In this way, it is helpful to control the surface morphology of the thin film deposition wafer actually obtained within the qualified range, improve the production yield, and reduce the waste of wafer materials.

[0073] In some embodiments, a method of preparing a thin film deposition wafer may include: adjusting parameters of a thin film deposition process according to a prediction result to compensate for the predicted surface morphology of the prepared wafer with respect to the growth surface morphology.

[0074] Here, compensating for the growth surface morphology means that, when preparing a thin film deposition wafer, a thin film deposition process with adjusted parameters is performed on the preliminary wafer to adjust the process of growing the surface morphology of the preliminary wafer or the process of forming the deposited thin film, so as to compensate for the surface morphology of the preliminary wafer by reducing the stress and stress accumulation generated in the preliminary wafer during the growth of the surface morphology.

[0075] In this way, the deformation degree of the surface morphology formed by the thin film deposition wafer actually obtained is reduced due to the above-mentioned compensation effect, so that the surface morphology can be closer to or meet the target surface morphology.

[0076] Exemplarily, adjusting the parameters of the thin film deposition process according to the prediction result may include: comparing the parameter value of the predicted surface morphology, such as the Warp value, with its corresponding threshold value, such as the Warp threshold value, and adjusting the parameters of the thin film deposition process when the parameter value exceeds the threshold value. In other words, the above compensation can be performed on the prepared wafers that are determined to be "unqualified".

[0077] In some embodiments of the method for preparing a thin film deposition wafer, adjusting the parameters of the thin film deposition process may include adjusting the growth parameters of the thin film deposition process. Here, the growth parameters of the thin film deposition process refer to parameters directly related to the growth surface morphology, such as temperature, pressure, gas flow rate, etc.

[0078] For example, the thickness of the thin film growth of the prepared wafer can be adjusted by adjusting the growth parameters of the thin film deposition process. In this way, the local deformation of the prepared wafer can be caused according to the different film stresses caused by different film thicknesses, thereby compensating for the local morphology of the prepared wafer.

[0079] When the film growth thickness of the prepared wafer is adjusted, the compensation value of the film growth thickness can be determined using the following formula (2): (2) in, are the polar coordinates of the sampling points on the surface of the prepared wafer, The other parameters with the same meaning as formula (1) are not described here.

[0080] In practical application, we can first replace Set to 0, the resulting This is the predicted surface topography height of the prepared wafer, based on which the predicted surface topography can be evaluated.

[0081] When it is evaluated that the predicted surface morphology cannot meet its corresponding target value, Set as the target value, the resulting That is, the compensation value required to make the predicted surface topography height value meet the standard.

[0082] According to another aspect of the present disclosure, a thin film deposition wafer is provided, which is obtained by using the method for preparing a thin film deposition wafer according to an embodiment of the present disclosure, wherein the thin film deposition wafer is an epitaxial wafer and the warpage of the thin film deposition wafer is less than 6500 nm.

[0083] like Fig.13 As shown, for two comparison wafers M and N with the same original warpage (indicated by M1 and N1), compared with the warpage N2 of the epitaxial wafer obtained by the preparation method of the comparison wafer according to the related art, the warpage M2 of the epitaxial wafer obtained by the method for preparing a thin film deposition wafer according to an embodiment of the present disclosure is significantly lower, that is, the degree of deformation is lower.

[0084] This shows that the method for preparing a thin film deposition wafer according to the embodiment of the present disclosure, with the aid of the estimation and compensation steps, can more specifically control the growth of the surface morphology of the thin film deposition wafer, which helps to make the prepared wafer have a lower degree of deformation and is closer to the surface morphology requirements after the actual thin film deposition process, which is beneficial to improving product yield.

[0085] Although the present disclosure has been described with reference to exemplary embodiments, it should be understood that the present disclosure is not limited to the specific embodiments described and shown in detail herein. Various changes may be made to the exemplary embodiments by those skilled in the art without departing from the scope defined by the claims of the present disclosure.

[0086] The features mentioned and / or shown in the above description of the exemplary embodiments of the present disclosure may be combined in the same or similar manner into one or more other embodiments, combined with features in other embodiments or substituted for corresponding features in other embodiments. The technical solutions obtained by these combinations or substitutions shall also be deemed to be included in the protection scope of the present disclosure. Therefore, the protection scope of the present disclosure shall be subject to the protection scope of the claims.

Claims

1. A method for predicting the surface morphology of a thin film deposition wafer, characterized in that: The method comprises: obtaining a predicted surface morphology of the prepared wafer after the thin film deposition process according to a surface morphology height of the prepared wafer and a surface morphology height difference corresponding to the thin film deposition process.

2. The method for predicting the surface morphology of a thin film deposition wafer according to claim 1, characterized in that: The surface morphology height difference corresponding to the thin film deposition process is obtained according to the deformation of the prepared wafer after the thin film deposition process characterized by a curve fitting method.

3. The method for predicting the surface morphology of a thin film deposition wafer according to claim 2, characterized in that: The surface topography height difference corresponding to the thin film deposition process is obtained according to the deformation characterized by the curvature of a circle fit, the curvature of a spherical fit or the constant term of a binomial parabola.

4. The method for predicting the surface morphology of a thin film deposition wafer according to claim 1, characterized in that: The thin film deposition process is at least one of a wafer front side thin film deposition process and a wafer back side thin film deposition process.

5. The method for predicting the surface morphology of a thin film deposition wafer according to claim 1, characterized in that: The surface topography height of the prepared wafer is measured by using a topography measuring instrument, and the measurement is sampled along the radial direction of the prepared wafer.

6. A method for preparing a thin film deposition wafer, characterized in that: include: Before performing a thin film deposition process on the prepared wafer, the method for predicting the surface morphology of a thin film deposition wafer according to any one of claims 1 to 5 is performed.

7. The method for preparing a thin film deposition wafer according to claim 6, characterized in that: include: The prepared wafers are graded and screened according to the prediction results.

8. The method for preparing a thin film deposition wafer according to claim 6, characterized in that: include: The parameters of the thin film deposition process are adjusted according to the prediction results to compensate the predicted surface morphology of the prepared wafer for the growth surface morphology.

9. The method for preparing a thin film deposition wafer according to claim 8, characterized in that: The adjusting the parameters of the thin film deposition process includes adjusting the growth parameters of the thin film deposition process.

10. A thin film deposition wafer, characterized in that: The method for preparing a thin film deposition wafer according to any one of claims 6 to 9 is obtained, wherein the thin film deposition wafer is an epitaxial wafer, and a warpage value of the thin film deposition wafer is less than 6500 nm.

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