CN110473909A - Standard wafer and its manufacturing method - Google Patents

Abstract

The present application discloses a standard wafer and a manufacturing method thereof. The standard wafer includes: a substrate; at least two types of thin film layers, and among the at least two types of thin film layers, different types of thin film layers contain different materials; at least two The different types of thin film layers are formed on different preset regions on the plane where the substrate is located. The present application arranges different types of thin film layers in different regions of the plane where the standard wafer is located. When using the standard wafer for calibration, different types of thin film layers can be calibrated at one time, without the need to replace multiple types of standard wafers, thereby The calibration steps are simplified and the calibration efficiency is improved.

Description

Standard wafer and its manufacturing method

technical field

The present application relates to the technical field of semiconductor manufacturing, in particular to a standard wafer and a manufacturing method thereof.

Background technique

With the development of the semiconductor manufacturing process, the process size is continuously reduced, and correspondingly, the thickness of the thin film in the semiconductor device is also continuously reduced. In order to maintain the uniformity of film thickness, higher requirements are put forward for the accuracy and stability of film thickness measurement. In order to ensure the accuracy and stability of the film thickness measurement, it is necessary to use a standard wafer (Wafer) to calibrate the measuring machine regularly.

In related technologies, standard wafers of various thin types are usually included: for example, silicon dioxide (SiO ₂ ) thin film standard wafers, silicon nitride (SiN) thin film standard wafers, polysilicon thin film standard wafers, etc.; at the same time, due to the consideration of precision , the standard wafers of each film type correspond to a variety of films with different thicknesses: taking silicon dioxide films as an example, they correspond to standard silicon dioxide film wafers with thicknesses T1, T2 and T3 respectively.

Fig. 1 shows the schematic diagram of the standard wafer that provides in the related art, as shown in Fig. 1, this standard wafer 100 is the silicon dioxide film standard wafer of thickness T1, when using this standard wafer 100, usually this standard wafer 100 is fixed on the measuring machine, and the measuring machine is calibrated by using the laser (Laser) irradiation area 110, and then another type or other thickness of the standard wafer is replaced and the calibration is performed again. The operation process is relatively cumbersome. At the same time, since the laser irradiates the region 110 every time the standard wafer 100 is used for calibration, the surface of the region 110 will be damaged during long-term use, thus affecting the calibration accuracy.

Contents of the invention

The present application provides a standard wafer and a manufacturing method thereof, which can solve the problem that the standard wafer provided in the related art is cumbersome to operate during the calibration process.

On the one hand, the present application provides a standard wafer, which is used to calibrate the thickness of the measuring bench machine in the semiconductor manufacturing process, including:

Substrate;

At least two types of film layers, among the at least two types of film layers, different types of film layers contain different materials;

The at least two types of thin film layers are formed on different predetermined regions of the plane where the substrate is located.

Optionally, each type of thin film layer includes at least two thicknesses, and thin film layers with different thicknesses are formed on different predetermined regions.

Optionally, each type of thin film layer includes at least two thicknesses, and thin film layers with different thicknesses are formed on different predetermined regions.

Optionally, among the at least two types of thin film layers, there is at least one type of thin film layer that satisfies the same thickness and is formed on different preset regions.

Optionally, there are thin film layers of the same type but different thicknesses located in adjacent preset regions.

Optionally, there are different types of thin film layers located in adjacent preset regions.

Optionally, the thin film layer includes at least one of nitride, oxide, polysilicon, high-K dielectric material, silicon germanium, titanium, platinum, and palladium.

In another aspect, the present application provides a method for manufacturing a standard wafer, the standard wafer is used for thickness calibration of a measuring bench machine in a semiconductor manufacturing process, the method comprising:

Step S1: providing a substrate;

Step S2: depositing a first type of thin film layer on the substrate;

Step S3: Removing the first-type thin-film layer in other regions in the preset region corresponding to the first-type thin-film layer in the mask;

Step S4: Deposit the i-th type of film layer in the other area, 2≤i≤n, n≥2, i and n are positive integers, n is the preset number of film layer types, the i-th type of film a layer comprising a material different from that of said first type of film layer;

Step S5: the preset area corresponding to the deposited thin film layer of the photomask, and remove the thin film layer in other areas by etching process, and the preset area corresponding to each type of thin film layer in the n types of thin film layers is different;

Step S6: set i=i+1, repeat step S4 and step S5 until i=n.

Optionally, each type of film layer includes at least two thicknesses, and film layers of different thicknesses are formed on the different preset regions, and the method further includes:

The thin film layers in the predetermined area are etched sequentially, so that each type of thin film layer includes at least two thicknesses.

Optionally, among the at least two types of thin film layers, there is at least one type of thin film layer that satisfies the same thickness and is formed on different preset regions.

Optionally, there are thin film layers of the same type but different thicknesses located in adjacent preset regions.

Optionally, there are different types of thin film layers located in adjacent preset regions.

Optionally, the thin film layer includes at least one of nitride, oxide, polysilicon, high-K dielectric material, silicon germanium, titanium, platinum, and palladium.

The technical solution of the present application at least includes the following advantages:

By setting different types of thin film layers in different areas of the plane where the standard wafer is located, when the standard wafer is used for calibration, different types of thin film layers can be calibrated at one time, and there is no need to replace multiple types of standard wafers, thus simplifying the process. A calibration step improves calibration efficiency.

Description of drawings

In order to more clearly illustrate the specific embodiments of the present application or the technical solutions in the prior art, the following will briefly introduce the accompanying drawings that need to be used in the description of the specific embodiments or prior art. Obviously, the accompanying drawings in the following description The drawings are some implementations of the present application, and those skilled in the art can obtain other drawings based on these drawings without creative work.

Fig. 1 is a schematic diagram of a standard wafer provided in the related art;

Fig. 2 is a schematic diagram of a standard wafer provided by an exemplary embodiment of the present application;

Fig. 3 is a schematic diagram of a standard wafer provided by an exemplary embodiment of the present application;

Fig. 4 is a flowchart of a method for manufacturing a standard wafer provided by an exemplary embodiment of the present application.

Detailed ways

The technical solutions in this application will be clearly and completely described below in conjunction with the accompanying drawings. Apparently, the described embodiments are part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the scope of protection of this application.

In the description of this application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" etc. The indicated orientation or positional relationship is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the referred device or element must have a specific orientation, use a specific orientation construction and operation, therefore should not be construed as limiting the application. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and should not be construed as indicating or implying relative importance.

In the description of this application, it should be noted that unless otherwise specified and limited, the terms "installation", "connection", and "connection" should be understood in a broad sense, for example, it can be a fixed connection or a detachable connection. Connection, or integral connection; it may be mechanical connection or electrical connection; it may be direct connection or indirect connection through an intermediary, or it may be the internal communication of two components, which may be wireless connection or wired connection connect. Those of ordinary skill in the art can understand the specific meanings of the above terms in this application in specific situations.

In addition, the technical features involved in the different embodiments of the present application described below may be combined as long as they do not constitute a conflict with each other.

Example 1:

Referring to FIG. 2 , it shows a schematic diagram of a standard wafer provided by an exemplary embodiment of the present application. As shown in FIG. 2 , the standard wafer 200 includes a substrate 210 and at least two types of thin film layers (two different types of thin film layers 221 and 222 are used as examples in FIG. 2 ).

Among the at least two types of film layers, different types of film layers contain different materials, for example, the film layer 221 is a silicon nitride film, and the film layer 222 is a silicon dioxide film; at least two types of film layers are formed in On different predetermined regions of the plane where the substrate 210 is located, for example, the thin film layer 221 and the thin film layer 222 are formed on different predetermined regions of the plane where the substrate 210 is located. Wherein, the preset area is an area on the plane where the substrate 210 is located. When preparing a standard wafer, it is necessary to divide a preset area on the plane where the substrate 210 is located for depositing a thin film layer.

To sum up, in this embodiment, by setting different types of thin film layers in different regions of the plane where the standard wafer is located, when using the standard wafer for calibration, different types of thin film layers can be calibrated at one time without replacement Various types of standard wafers simplify calibration steps and improve calibration efficiency.

Example 2:

Referring to Example 1, the difference between Example 2 and Example 1 is that each type of film layer includes at least two thicknesses, and film layers of different thicknesses are formed on different predetermined regions. The thickness relationship between different types of film layers is not limited.

For example, a standard wafer includes two types of film layers: silicon nitride film and silicon dioxide film, while silicon nitride film includes three thicknesses of T1, T2 and T3, and silicon dioxide film includes three thicknesses of T4, T5 and T6 , then the silicon nitride film of T1 thickness, the silicon nitride film of T2 thickness, the silicon nitride film of T3 thickness, the silicon dioxide film of T4 thickness, the silicon dioxide film of T5 thickness and the silicon dioxide film of T6 thickness respectively Formed in different preset areas.

In this embodiment, by setting different types of thin film layers in different regions of the plane where the standard wafer is located, and each type of thin film layer includes at least two thicknesses, when using the standard wafer for calibration, different types can be calibrated at one time, Moreover, the thin film layers with different thicknesses are calibrated without replacing standard wafers of various types and thicknesses, which further simplifies the calibration steps and improves the calibration efficiency.

Example 3:

Referring to Example 2, the difference between Example 3 and Example 2 lies in that among at least two types of thin film layers, there is at least one type of thin film layer that satisfies the same thickness and is formed on different preset regions.

For example, a standard wafer includes two types of film layers: a silicon nitride film and a silicon dioxide film, the silicon nitride film includes three thicknesses of T1, T2 and T3, and the silicon nitride film of T1 thickness is located in the first preset area and In the second preset area, the silicon nitride film with a thickness of T2 is located in the third preset area and the fourth preset area, and the silicon nitride film with a thickness of T3 is located in the fifth preset area and the sixth preset area; the silicon dioxide film Including three thicknesses of T4, T5 and T6, the silicon dioxide film of T4 thickness is located in the seventh preset area and the eighth preset area, and the silicon dioxide film of T5 thickness is located in the ninth preset area and the tenth preset area, A silicon dioxide film with a thickness of T6 is located in the eleventh preset area and the twelfth preset area. It should be noted that this embodiment is only an example, and the film layers of the same thickness can be formed in different preset regions, and can also be formed in a preset region, as long as there is one type of film layer, the same thickness distribution Just in different preset areas.

In this embodiment, by distributing the same thickness and the same type of film layers in different preset areas, when one of the film layers is damaged due to long-term use, the same type and the same thickness of the film in another preset area can be used layer for calibration.

Example 4:

Referring to Example 3, the difference between Example 4 and Example 3 lies in that there are film layers of the same type but different thicknesses located in adjacent predetermined regions. For example, in the above embodiments, the silicon nitride layer with a thickness of T1 and the silicon nitride layer with a thickness of T2 may be located in adjacent preset regions.

Example 5:

Referring to Example 3 and Example 4, the difference between Example 5 and Example 3 and Example 4 lies in that there are different types of thin film layers located in adjacent predetermined areas. For example, in the above embodiments, the silicon oxide layer and the silicon dioxide layer may be located in adjacent preset regions.

Optionally, the thin film layer in the embodiment of the present application includes nitride (such as silicon nitride), oxide (such as silicon dioxide), polysilicon, high-K dielectric material (such as a material with a dielectric constant "K" greater than 10) , silicon germanium, titanium, platinum, palladium at least one.

An exemplary embodiment of the present application is described by taking an example that a standard wafer includes three types of thin film layers, and each type of thin film layer includes two thicknesses. As shown in FIG. 3 , the standard wafer 300 provided in this embodiment includes a substrate 310 and a thin film layer, and the thin film layer includes a first type thin film layer 3111 with a T1 thickness, a first type thin film layer 3112 with a T2 thickness, The second type of film layer 3121 of T3 thickness, the second type of film layer 3122 of T4 thickness, the third type of film layer 3131 of T5 thickness, and the third type of film layer 3132 of T6 thickness. Wherein, the thickness of T1 is different from that of T2, the thickness of T3 is different from that of T4, the thickness of T5 is different from that of T6, and the thickness relationship between different types of film layers is not limited.

As shown in FIG. 3 , film layers of the same thickness are located in different predetermined areas; film layers of the same type but with different thickness are located in adjacent areas; and film layers of different types are located in adjacent areas.

Embodiment 6:

Referring to FIG. 4 , it shows a flowchart of a method for manufacturing a standard wafer provided by an exemplary embodiment of the present application. The standard wafer provided by the above-mentioned embodiments can be manufactured by this method, and the method includes:

Step S1, providing a substrate.

Step S2, depositing a first type thin film layer on the substrate.

In step S3 , mask the predetermined area corresponding to the first type of thin film layer, and remove the first type of thin film layer in other areas through an etching process.

Step S4, depositing the i-th type thin film layer in other areas, 2≤i≤n, n≥2, i and n are positive integers, n is the preset number of thin film layer types, the i-th type thin film layer and the The first type of film layer comprises different materials.

In step S5, the predetermined area corresponding to the deposited thin film layer of the photomask is removed by etching process, and the predetermined area corresponding to each type of thin film layer in the n types of thin film layers is different.

Step S6, set i=i+1, repeat step S4 and step S5 until i=n.

Taking n=3 as an example, Embodiment 6 is described:

After step 403, a second type of thin film layer is deposited in other areas; the preset area corresponding to the first type thin film layer and the second type thin film layer of the photomask is etched to the second type thin film layer in other areas layer is removed; a third type of thin film layer is deposited in other areas; the preset area corresponding to the first type of thin film layer, the second type of thin film layer and the third type of thin film layer is masked, and the other areas are etched through the etching process The third type of film layer is removed.

In the above embodiment, when each type of thin film layer corresponds to a different thickness, the method further includes: sequentially etching the thin film layers in the predetermined area, so that each type of thin film layer includes at least two thicknesses.

The thin film layer can be deposited to the maximum thickness first, and the predetermined area corresponding to the thin film layer with a larger thickness is gradually masked, and the predetermined area corresponding to other thicknesses is etched to obtain a thin film layer with a lower thickness.

For example, a standard wafer includes two types of thin film layers: the first type thin film layer and the second type thin film layer, the first type thin film layer corresponds to two thicknesses T1 and T2 and (T1>T2), the second type thin film layer The thin film layer corresponding to two kinds of thicknesses T3 and T4 (T3>T4), can deposit the first type thin film layer of T1 thickness and the second type thin film layer of T3 thickness by above-mentioned method; To the first type thin film layer of T1 thickness Perform a photomask on the preset area corresponding to the second type of thin film layer, and etch the first type thin film layer of T1 thickness in other areas to obtain the first type thin film layer of T2 thickness; for the first type of thin film layer of T1 thickness type thin film layer, the second type thin film layer with T2 thickness and the preset area corresponding to the second type thin film layer with T3 thickness are masked, and the second type thin film layer with T3 thickness in other areas is etched to obtain The second type of film layer of T4 thickness.

Apparently, the above-mentioned embodiments are only examples for clear description, rather than limiting the implementation. For those of ordinary skill in the art, on the basis of the above description, other changes or changes in different forms can also be made. It is not necessary and impossible to exhaustively list all the implementation manners here. However, the obvious changes or changes derived therefrom are still within the protection scope of the invention of the present application.

Claims (12)

1. a standard wafer, is characterized in that, described standard wafer is used for carrying out thickness calibration to the measuring bench machine in the semiconductor manufacturing process, comprising: Substrate; At least two types of film layers, among the at least two types of film layers, different types of film layers contain different materials; The at least two types of thin film layers are formed on different predetermined regions of the plane where the substrate is located. 2 . The standard wafer according to claim 1 , wherein each type of thin film layer comprises at least two thicknesses, and thin film layers with different thicknesses are formed on the different predetermined regions. 3 . The standard wafer according to claim 2 , wherein, among the at least two types of thin film layers, there is at least one type of thin film layer that satisfies the same thickness and is formed on different preset regions. 4 . 4 . The standard wafer according to claim 3 , wherein there are thin film layers of the same type but with different thicknesses located in adjacent preset regions. 5. The standard wafer according to claim 3 or 4, characterized in that there are different types of thin film layers located in adjacent preset regions. 6. The standard wafer according to any one of claims 1 to 5, wherein the thin film layer comprises at least one of nitride, oxide, polysilicon, high-K dielectric material, silicon germanium, titanium, platinum, palladium kind. 7. A method for manufacturing a standard wafer, characterized in that, the standard wafer is used for thickness calibration of a measuring bench machine in a semiconductor manufacturing process, and the method comprises: Step S1: providing a substrate; Step S2: depositing a first type of thin film layer on the substrate; Step S3: Removing the first-type thin-film layer in other regions in the preset region corresponding to the first-type thin-film layer in the mask; Step S4: Deposit the i-th type of film layer in the other area, 2≤i≤n, n≥2, i and n are positive integers, n is the preset number of film layer types, the i-th type of film a layer comprising a material different from that of said first type of film layer; Step S5: the preset area corresponding to the deposited thin film layer of the photomask, and remove the thin film layer in other areas by etching process, and the preset area corresponding to each type of thin film layer in the n types of thin film layers is different; Step S6: set i=i+1, repeat step S4 and step S5 until i=n. 8. The method according to claim 7, wherein said each type of film layer comprises at least two thicknesses, and film layers of different thicknesses are formed on said different preset regions, said method further comprising : The thin film layers in the predetermined area are etched sequentially, so that each type of thin film layer includes at least two thicknesses. 9 . The method according to claim 8 , wherein, among the at least two types of thin film layers, there is at least one type of thin film layer that satisfies the same thickness and is formed on different predetermined regions. 10 . The method according to claim 9 , wherein there are thin film layers of the same type but different thicknesses located in adjacent preset regions. 11 . 11. The method according to claim 9 or 10, characterized in that there are different types of film layers located in adjacent predetermined areas. 12. The method according to any one of claims 6 to 11, wherein the thin film layer comprises at least one of nitrides, oxides, polysilicon, high-K dielectric materials, silicon germanium, titanium, platinum, and palladium .