KR101116656B1 - Method for inspecting a wafer shape and method for heat treatment a wafer using the same - Google Patents

Abstract

A wafer shape inspection method is disclosed. The wafer is placed on a plate with a different temperature than the wafer. Then, after placing the wafer, the first and second temperatures of the plate are measured at positions corresponding to each of the center and the edge of the placed wafer after a certain time elapses. Next, each of the first and second temperatures is compared with each of the first and second reference temperatures to determine whether the shape of the wafer is convex or concave. Therefore, it is possible to inspect whether the shape of the wafer is convex or concave directly at the place where the wafer is heat treated.

Description

METHOD FOR INSPECTING A WAFER SHAPE AND METHOD FOR HEAT TREATMENT A WAFER USING THE SAME

The present invention relates to a wafer shape inspection method and a wafer heat treatment method using the same, and more particularly, to a method of inspecting a shape of a wafer used to manufacture a semiconductor device and a method of heat treating the wafer by applying the same.

In general, semiconductor devices are fabricated from wafers based on silicon. Specifically, the semiconductor device is manufactured by performing a deposition process, a photolithography process, an etching process, an ion implantation process, a cleaning process, an inspection process, and the like on the wafer.

Among the above processes, in order to form a desired pattern on the wafer, a photolithography process is performed by uniformly applying a photoresist film uniformly to the wafer, exposing through a patterned mask on the photoresist film, and then applying a developer to the pattern of the mask. By advancing | eliminating a part of the said photosensitive film | membrane, it advances.

At this time, during the photolithography process, before the coating of the photoresist film, after the photoresist film is exposed, and after the part of the photoresist film is removed with the developer, the step of heat-treating the portion on which the photoresist film of the wafer is to be formed or formed is performed. Proceed.

The reason for the heat treatment of the wafer may be to remove moisture from the surface of the wafer so that the photoresist film is applied to the wafer and adhere to the wafer, or to harden the photoresist film so that the exposed photoresist film is clearly distinguished from the exposed part. This is to completely remove the solvent portion of the developer deposited on the photosensitive film.

In particular, since the heat treatment process performed after the exposure directly affects the critical dimension (CD) of the pattern formed on the photosensitive film, it is essential to provide heat uniformly to the wafer.

To this end, before proceeding with the heat treatment process, it is checked whether the shape of the wafer is convex or concave through the previous deposition process, and accordingly, the center and the edges of the wafer are sucked and planarized in different orders, The center and the edge of the wafer are heated to different temperatures.

However, as the process of inspecting the wafer shape of the wafer is performed through a laser displacement sensor at an inspection place different from the heat treatment place for proceeding the heat treatment process, an operation of transferring the wafer is added, thereby reducing process efficiency. have.

Accordingly, the present invention has been made in view of such a problem, and an object of the present invention is to provide a wafer shape inspection method which can improve process efficiency by inspecting wafer shape directly on a plate on which heat treatment is performed.

Another object of the present invention is to provide a wafer heat treatment method to which the above-described wafer shape inspection method is applied.

In order to achieve the above object of the present invention, a wafer shape inspection method according to one aspect is disclosed.

The wafer is placed on a plate having a different temperature than the wafer. Then, after the wafer is placed, the first and second temperatures of the plate are measured at positions corresponding to each of the center and the edge of the placed wafer after a predetermined time elapses.

Next, each of the first and second temperatures is compared with each of the first and second reference temperatures to determine whether the shape of the wafer is convex or concave.

Thus, after the plate is heated before placing the wafer on the plate, a process of stopping the heating of the plate may be added when the heated plate reaches a predetermined temperature.

In addition, when measuring the first and second temperatures, the predetermined time may be 2 to 5 seconds.

In order to achieve the above object of the present invention, a wafer heat treatment method according to one aspect is disclosed.

The wafer is placed on a plate having a different temperature than the wafer. Then, after the wafer is placed, the first and second temperatures of the plate are measured at positions corresponding to each of the center and the edge of the placed wafer after a predetermined time elapses.

Next, each of the first and second temperatures is compared with each of the first and second reference temperatures to determine whether the shape of the wafer is convex or concave. Subsequently, the wafer is flattened by sucking the center and the edge of the wafer from the bottom in different order according to the determined shape of the wafer.

The plate is then heated to heat treat the planarized wafer.

Here, when the wafer is planarized, the wafer may be sucked from the edge to the center or from the center to the edge, depending on whether the shape of the wafer is convex or concave.

In order to achieve the above object of the present invention, a wafer heat treatment method according to another feature is disclosed.

The wafer is placed on a plate having a different temperature than the wafer. Then, after the wafer is placed, the first and second temperatures of the plate are measured at positions corresponding to each of the center and the edge of the placed wafer after a predetermined time elapses.

Next, each of the first and second temperatures is compared with each of the first and second reference temperatures to determine whether the shape of the wafer is convex or concave. Subsequently, the plate is heated to different temperatures at positions corresponding to each of the center and the edge of the wafer according to the determined shape of the wafer to uniformly heat-treat the wafer.

Here, when the wafer is heat-treated, the plate may be heated to a lower temperature at an edge position than the center position of the wafer or at the center position than the edge position depending on whether the shape of the wafer is convex or concave.

According to such a wafer shape inspection method and a wafer heat treatment method to which the wafer is applied, the process of inspecting whether the wafer is convex or concave is directly inspected on a plate substantially heat-treating the wafer, whereby the wafer is unnecessarily another place for the inspection process. The efficiency of the process of heat-treating the wafer may be improved by removing the operation of transferring the wafer.

As a result, the productivity of the semiconductor device manufactured from the wafer may be expected by improving the efficiency of the photolithography process including the heat treatment process of the wafer.

In addition, by using the temperature sensors that control the heating temperature of the plate as a means for inspecting the shape of the wafer, it is possible to reduce the process cost by removing the laser displacement sensor described in the background art.

Hereinafter, with reference to the accompanying drawings will be described in detail a wafer shape inspection method and a wafer heat treatment method applying the same according to an embodiment of the present invention. As the invention allows for various changes and numerous embodiments, particular embodiments will be illustrated in the drawings and described in detail in the text. However, this is not intended to limit the present invention to the specific disclosed form, it should be understood to include all modifications, equivalents, and substitutes included in the spirit and scope of the present invention. Like reference numerals are used for like elements in describing each drawing. In the accompanying drawings, the dimensions of the structures are shown in an enlarged scale than actual for clarity of the invention.

The terms first, second, etc. may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be referred to as the second component, and similarly, the second component may also be referred to as the first component.

The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting of the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this application, the terms "comprises", "having", and the like are used to specify that a feature, a number, a step, an operation, an element, a part or a combination thereof is described in the specification, But do not preclude the presence or addition of one or more other features, integers, steps, operations, components, parts, or combinations thereof.

On the other hand, unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art. Terms such as those defined in the commonly used dictionaries should be construed as having meanings consistent with the meanings in the context of the related art and shall not be construed in ideal or excessively formal meanings unless expressly defined in this application. Do not.

FIG. 1 is a schematic view showing a wafer heat treatment apparatus according to an embodiment of the present invention, and FIG. 2 is a view illustrating a position where temperature sensors and vacuum ports of the wafer heat treatment apparatus illustrated in FIG. 1 are disposed.

1 and 2, a wafer heat treatment apparatus 1000 according to an embodiment of the present invention includes a plate 100, a plurality of temperature sensors 200, a heat generating unit 300, and a controller 400. do.

The wafer W is placed on the plate 100. Here, the wafer (W) is made of a silicon material is used to manufacture a semiconductor device. The wafer W usually has a circular shape.

In this case, a plurality of support pins 110 for supporting the wafer W are installed on the upper surface of the plate 100. The support pins 110 may prevent the wafer W from being directly contacted with the plate 100, thereby preventing the wafer W from being contaminated from the plate 100.

In addition, the support pins 110 are uniformly provided to the wafer W by partially spreading the heat provided from the plate 100 to be described below, between the plate 100 and the wafer W. You can do that.

In addition, a plurality of guide protrusions 120 are installed on the upper surface of the plate 100 to guide the position where the wafer W is placed. The guide protrusions 120 guide the side surfaces of the wafer W to align the wafer W placed on the plate 100.

In addition, each of the guide protrusions 120 has an inclined surface (not shown) inclined toward the center of the plate 100 at an upper portion thereof, such that the wafer W is guided to a predetermined difference. Even if placed incorrectly in the field, it can be naturally aligned by the inclined surface.

The temperature sensors 200 are embedded in the plate 100 to sense the temperature of the plate 100. In detail, the temperature sensors 200 correspond to the middle area MA of the wafer W between the center area CA, the edge area EA, and the center area CA and the edge area EA. The plate 100 is built in a constant arrangement.

In addition, the plate 100 is provided with a plurality of vacuum ports 130 are provided with an external vacuum pressure (VP). The vacuum ports 130 are formed in a predetermined arrangement on the plate 100 corresponding to the center area CA, the edge area EA, and the middle area MA of the wafer W. The vacuum ports 130 suck the wafer W through the vacuum pressure VP so that the wafer W is flatly supported and fixed to the support pins 110.

The heat generating part 300 is disposed on the bottom surface of the plate 100. The heat generating unit 300 generates heat by driving power applied from the outside and transfers the heat to the plate 100. As a result, the plate 100 heats and heats the wafer W through the heat transferred from the heat generating part 300.

The heating part 300 may be patterned in a thin plate shape on the lower surface of the plate 100. Alternatively, the heat generating unit 300 may be embedded in the plate 100 so as not to interfere with the temperature sensors 200.

The controller 400 is connected to the temperature sensors 200 and the heat generator 300. The control unit 400 receives the sensed temperature from the temperature sensors 200 and controls driving power applied to the heat generating unit 300. That is, the controller 400 controls the plate 100 to be heated to a predetermined temperature by the heat generator 300.

On the other hand, the wafer heat treatment apparatus 1000 is a chamber (not shown) for preventing the heat provided from the plate 100 to the wafer (W) to leak outside from a predetermined space including the wafer (W) It may further include.

The chamber may be configured such that both the plate 100 and the heat generating part 300 may be disposed therein, such as the wafer W, and only covers the wafer W on the upper surface of the plate 100. It may be configured to.

Hereinafter, a method of heat treating the wafer by the wafer heat treatment apparatus will be described in detail with reference to FIGS. 3 to 6.

3 is a flowchart illustrating a process of heat treating a wafer according to an embodiment using the wafer heat treatment apparatus illustrated in FIG. 1.

Referring to FIG. 3, in the method of thermally processing a wafer according to an embodiment, first, driving power is applied to the heat generating part 300 through the control part 400 to heat the plate 100 (S10). .

Subsequently, when the plate 100 reaches a predetermined temperature through the temperature sensors 200, the driving power applied to the heat generating unit 300 is cut off to stop heating of the plate 100 (S20).

In this case, the predetermined temperature at which the heating of the plate 100 is stopped may be higher than room temperature so that heat from the plate 100 can easily escape from the temperature of the wafer W at room temperature. The constant temperature may be, for example, about 50 ° C.

Subsequently, the wafer W is placed on the support pins 110 of the plate 100 to be guided by the guide protrusions 120 (S30). Subsequently, the first and second temperatures T1 and T2 of the plate 100 are measured through the temperature sensors 200 at positions corresponding to the center and the edge of the wafer W (S40). In this case, the first and second temperatures T1 and T2 are measured after a predetermined time elapses after placing the wafer W on the support pins 110 of the plate 100.

Therefore, if the predetermined time is less than about 2 seconds, it is not preferable because the heat from the plate 100 is too short to discharge to the wafer W. If the predetermined time is longer than about 5 seconds, the wafer W may be removed. This is undesirable because it affects the overall process time for heat treatment. Therefore, the first and second temperatures T1 and T2 are preferably measured after about 2 to 5 seconds after placing the wafer W on the support pins 110 of the plate 100.

Next, the shape of the wafer W is inspected by comparing each of the first and second temperatures T1 and T2 with the first and second reference temperatures ST1 and ST2, respectively (S50). .

Herein, a method of calculating the first and second reference temperatures ST1 and ST2 will be briefly described. First, a standard having the same size as the wafer W and having flatness certified through a separate measuring device. Prepare the wafer. Next, the plate 100 is heated to a predetermined temperature through the steps S10 and S20. Next, the reference wafer prepared above is placed on the support pins 110 of the plate 100. Next, the reference wafer is placed on the support pins 110 of the plate 100, and then, after a predetermined time, the first and second references of the plate 100 are positioned at positions corresponding to the center and the edge of the reference wafer. The temperatures ST1 and ST2 are measured.

Here, the first and second reference temperatures ST1 and ST2 are measured through the temperature sensors 200 which measured the first and second temperatures T1 and T2 substantially. The same time as when the first and second temperatures T1 and T2 are measured.

Subsequently, when each of the first and second temperatures T1 and T2 is the same as each of the first and second reference temperatures ST1 and ST2, the wafer W is determined to be flat and the vacuum port is determined. By simultaneously providing a vacuum pressure (VP) to the 130 so that the wafer (W) is supported and fixed to the support pins (110) (S60).

Subsequently, a driving power is applied to the heat generating part 300 to heat the plate 100, thereby providing uniform heat to the wafer W to heat-treat the wafer W (S70). For example, when the wafer W is to be subjected to heat treatment after exposure, the plate 100 may heat-treat the wafer W at about 100 ° C.

However, since the wafer W generally has a 휜 shape through a previous deposition process, each of the first and second temperatures T1 and T2 may have the first and second reference temperatures ST1 and ST2. Are rarely generated, and one of the first and second temperatures T1 and T2 is likely to be different from the first and second reference temperatures ST1 and ST2.

Hereinafter, a method of inspecting a phenomenon in which the wafer is convexly curved or concave is further described with reference to FIGS. 4 and 5.

4 is a view illustrating a case where a wafer is convex during the heat treatment shown in FIG. 3, and FIG. 5 is a view illustrating a case where the wafer is concave during the heat treatment shown in FIG. 3.

Referring further to FIG. 4, if each of the first and second temperatures T1 and T2 is different from the first and second reference temperatures ST1 and ST2, the first temperature T1 may be equal to the above. It is compared whether it is higher than 1st reference temperature ST1 (S80).

Accordingly, when the first temperature T1 is higher than the first reference temperature ST1, it is determined that the shape of the wafer W is convex. This is because the heat of the plate 100 is less dissipated from the center of the wafer W than the reference wafer, so that the center of the wafer W is farther from the plate 100 than the reference wafer. Because it is located.

In this case, the vacuum pressure VP is provided to the vacuum ports 130 in the order so that the wafer W is sucked in the center order from the edge, thereby providing the wafer W to the support pin 110. Flatten to the support to fix (S90).

Thus, when the wafer W has a convexly concave shape, it is possible to prevent breakage of the wafer W that may be generated by simultaneously providing the vacuum pressure VP to the vacuum ports 130. Can be.

On the contrary, referring to FIG. 5, if the first temperature T1 is not greater than the first reference temperature ST1, it is compared whether the second temperature T2 is higher than the second reference temperature ST2 ( S85).

Accordingly, when the second temperature T2 is higher than the second reference temperature ST2, it is determined that the shape of the wafer W is concave. This is because the heat of the plate 100 is less dissipated than the reference wafer at the edge of the wafer W, so that the edge of the wafer W is farther from the plate 100 than the reference wafer. It is because it is located.

In this case, the vacuum pressure VP is provided to the vacuum ports 130 in the order of the edges in the edge order from the center, thereby providing the wafer W to the support pin 110. Flattening to the support is fixed (S95).

Thus, even when the wafer W has a concave concave shape, similarly to the convex concave shape, the wafer W may be generated by simultaneously providing the vacuum pressure VP to the vacuum ports 130. It is possible to prevent breakage of the wafer W.

The wafer W flattened on the support pins 110 of the plate 100 according to the steps S90 and S95 is heated by heating the plate 100 according to the step S70.

As such, when the wafer W is planarized to uniformly provide heat to the wafer W, the shape of the wafer W that determines the order of sucking the center and the edge of the wafer W is convex. Alternatively, by inspecting whether the recess W is substantially on the plate 100 for heat treatment of the wafer W, the operation of unnecessarily transferring the wafer W for the shape inspection of the wafer can be eliminated. Thereby, the efficiency of the process of heat-processing the said wafer W can be improved.

As a result, the productivity of the semiconductor device manufactured from the wafer W may be improved by improving the efficiency of the photolithography process including the heat treatment process of the wafer W.

In addition, as a means for inspecting the shape of the wafer (W), by utilizing the temperature sensor 200 for controlling the heating temperature of the plate 100 as it is, the process cost by removing the laser displacement sensor described in the background art You can also save.

On the other hand, if the wafer W does not satisfy the conditions in steps S50, S80, and S85, the wafer W is determined to have an unusual shape other than concave, convex, and the like. It is necessary to carry out overhaul by taking out (W) to the outside.

6 is a flowchart illustrating a process of heat treating a wafer according to another exemplary embodiment through the wafer heat treatment apparatus illustrated in FIG. 1.

This embodiment compares the first and second temperatures measured from the plate with the first and second reference temperatures, except for the method of heat treating the wafer depending on whether the shape of the wafer is convex or concave. Since the same process is the same, the same reference numerals are used for the same process, and detailed description thereof will be omitted.

Referring to FIG. 6, if each of the first and second temperatures T1 and T2 of the plate 100 is measured to be the same as each of the first and second reference temperatures ST1 and ST2, the wafer is measured. It is determined that (W) is flat, and thus heats the wafer (W) by heating the plate 100 to a uniform temperature as a whole through the heat generating unit 300 (S61).

On the contrary, if the first temperature T1 of the plate 100 is measured to be higher than the first reference temperature ST1, it is determined that the shape of the wafer W is convex, and thus, the heat generating part 300 is used. The plate 100 is heated to a lower temperature at an edge position than the center position of the wafer W to heat-treat the wafer W (S91).

In addition, if the second temperature T2 of the plate 100 is measured to be higher than the second reference temperature ST2, it is determined that the shape of the wafer W is concave, so that the wafer is transferred through the heat generating part 300. The wafer 100 is heat-treated by heating the plate 100 to a lower temperature at the center position than the edge position of (W) (S96).

As such, the wafer W may be uniformly heat treated by heating the plate 100 to different temperatures at the center position and the edge position of the wafer W according to the shape of the wafer W. have.

While the present invention has been described in connection with what is presently considered to be practical and exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

The present invention described above can be used in a wafer heat treatment method that can improve the process efficiency by eliminating the operation of transferring the wafer unnecessarily by directly inspecting the shape of the wafer at the heat treatment place when heat treating the wafer. .

1 is a schematic view showing a wafer heat treatment apparatus according to an embodiment of the present invention.

FIG. 2 is a view illustrating a position where temperature sensors and vacuum ports of the wafer heat treatment apparatus illustrated in FIG. 1 are disposed.

3 is a flowchart illustrating a process of heat treating a wafer according to an exemplary embodiment through the wafer heat treatment apparatus illustrated in FIG. 1.

FIG. 4 is a diagram illustrating a case in which a wafer is convex during the heat treatment shown in FIG. 3.

FIG. 5 is a diagram illustrating a case where a wafer is concave during the heat treatment shown in FIG. 3.

6 is a flowchart illustrating a process of heat treating a wafer according to another exemplary embodiment through the wafer heat treatment apparatus illustrated in FIG. 1.

<Explanation of symbols for the main parts of the drawings>

W: Wafer 100: Plate

110: support pin 120: guide protrusion

130: vibration port 200: temperature sensor

300: heat generating unit 400: control unit

1000: Wafer Heat Treatment Equipment

Claims (7)

delete delete delete Placing the wafer on a plate having a different temperature than the wafer; Placing the wafer and then measuring the first and second temperatures of the plate at a position corresponding to each of the center and edge of the placed wafer after a period of time; Comparing each of the first and second temperatures with each of the first and second reference temperatures to determine whether the shape of the wafer is convex or concave; Planarizing the wafer by sucking the center and the edge of the wafer in a different order from the bottom according to the determined shape of the wafer; And Heating the plate to heat treat the planarized wafer. The method of claim 4, wherein in the planarizing of the wafer, the wafer is sucked in the center order from the edge or in the center order from the edge depending on whether the shape of the wafer is convex or concave. delete delete

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