JP2023002156A - Liquid processing device and liquid processing method - Google Patents

Abstract

To control the temperature distribution within a substrate surface when a paddle is formed on a substrate and the substrate is subjected to liquid processing.SOLUTION: A liquid processing device that performs liquid processing with processing liquid on a substrate includes: a substrate holding portion that holds and rotates the substrate; and a spray nozzle positioned above the substrate held by the substrate holding portion and spraying liquid that does not promote the liquid processing onto an in-plane area of the substrate including the center of the substrate.SELECTED DRAWING: Figure 1

Description

The present disclosure relates to a liquid processing apparatus and a liquid processing method.

In Patent Document 1, a developing solution is supplied from a nozzle onto an object to be processed held by a chuck device, and after a certain period of time has passed, a spinner constituting the chuck device is rotated to shake off the developing solution on the object to be processed. The paddle-type photoresist developing device includes a nozzle for mixing the developer and air to eject the developer in the form of a mist, and at least a part of the developer pipe leading to the nozzle is in the circulation path of the temperature-controlled water. Disclosed is a developing device arranged.

Japanese Patent Application Laid-Open No. 2004-274028

The technique according to the present disclosure controls the temperature distribution in the substrate surface when forming a puddle of the processing liquid on the substrate and liquid processing the substrate.

One aspect of the present disclosure is a liquid processing apparatus that performs liquid processing on a substrate with a processing liquid, comprising: a substrate holding unit that holds and rotates the substrate; A spray nozzle is positioned to spray a liquid that does not promote the liquid treatment onto an in-plane region of the substrate, including the center of the substrate.

According to the present disclosure, it is possible to control the temperature distribution within the surface of the substrate when the puddle of the processing liquid is formed on the substrate and the substrate is liquid-processed.

2 is a side cross-sectional view schematically showing the outline of the configuration of the developing device according to the embodiment; FIG. FIG. 4 is an explanatory diagram showing a process sequence of a developing method according to an embodiment; 5 is a graph showing changes over time in temperature at the center and edge of a wafer on which a puddle of developer is formed; FIG. 10 is a graph showing changes in temperature over time at the center and edge of a wafer when a puddle of developer is sprayed onto the wafer. FIG. FIG. 10 is a graph showing changes in temperature over time at the center and edge of a wafer when the wafer is sprayed once before the puddle is formed; FIG. FIG. 10 is a graph showing changes in temperature over time at the center and edge of a wafer when the wafer is sprayed three times before the puddle is formed; FIG. FIG. 4 is an explanatory view showing a state of spraying from above a position eccentric from the center of a wafer; FIG. 4 is a plan view of a wafer showing a spray area when spraying from above a position off-center from the center of the wafer; It is explanatory drawing which shows a mode that it is spraying from diagonally above the wafer. It is explanatory drawing which shows a mode that it is spraying by the spray nozzle which has two spray parts.

For example, in the manufacturing process of semiconductor devices, a resist film is formed on the surface of a substrate such as a semiconductor wafer (hereinafter sometimes referred to as a "wafer"), and a liquid treatment is performed in which a pattern is exposed and then developed. When developing, a puddle (liquid pool) of developer is formed on the substrate for development.

In this case, if the in-plane temperature of the substrate during puddle development is nonuniform, the uniformity of the dimension of the line width of the pattern after development deteriorates. That is, during puddle development, for example, there is a difference in temperature fluctuation from the center portion to the edge portion of the substrate, and as a result, variation occurs in the line width of the pattern from the center portion to the edge portion of the substrate. In particular, this tendency was conspicuous in i-line resists and the like, which have high temperature sensitivity during development processing.

In the technique described in Patent Document 1, at least a part of the developer pipe leading to a nozzle that mixes the developer and air and ejects the developer in the form of mist is arranged in the circulation path of the temperature-controlled water. However, there is room for improvement in in-plane temperature uniformity during puddle development.

Therefore, the technology according to the present disclosure controls the temperature distribution within the substrate surface when a paddle is formed on the substrate and the substrate is developed. As a result, liquid processing such as development can be controlled for each region, and, for example, it is possible to improve the uniformity of the line width within the surface of the substrate after development.

The configuration of the developing device according to this embodiment will be described below with reference to the drawings. In this specification, elements having substantially the same functional configuration are denoted by the same reference numerals, thereby omitting redundant description.

FIG. 1 shows a side cross-sectional view schematically showing the outline of the configuration of a developing device 1 as a liquid processing device according to this embodiment. The developing device 1 has a spin chuck 11 as a substrate holder in a housing 10 . The spin chuck 11 horizontally holds a wafer W as a substrate. The spin chuck 11 is connected to a rotating portion 12 that can move up and down, and the rotating portion 12 is connected to a rotation driving portion 13 configured by a motor or the like. Therefore, the held wafer W can be rotated by the driving of the rotation drive unit 13 .

A cup 21 is arranged outside the spin chuck 11 to prevent scattering of developer, cleaning liquid, and their mist from scattering around. A drain pipe 23 and an exhaust pipe 24 are provided at the bottom 22 of the cup 21 . The drainage pipe 23 leads to a drainage device 25 such as a drainage pump. The exhaust pipe 24 communicates through a valve 26 with an exhaust device 27 such as an exhaust pump. With this configuration, the atmosphere around the wafer W held by the spin chuck 11 is exhausted through the exhaust pipe 24 . Therefore, the exhaust pipe 24 and the exhaust device 27 constitute an exhaust section.

An air blower 14 is provided above the housing 10 of the developing device 1 to supply air of required temperature and humidity into the cup 21 as a downward flow.

When forming a puddle of developer on wafer W, developer nozzle 31 is used. The developer nozzle 31 is provided on a nozzle support 32 such as an arm. , and can move horizontally as indicated by a reciprocating arrow B (X direction) indicated by a dashed line. The developer nozzle 31 is supplied with a developer from a developer supply source 34 through a supply pipe 33 .

In forming the paddle, when using a so-called elongated nozzle having a discharge port longer than the diameter of the wafer W, the wafer W is scanned from one end to the other end. A puddle of developer can be formed thereon. In the case of a so-called straight type nozzle that ejects liquid so as to form a liquid column with a width sufficiently small relative to the diameter of the wafer W, the ejection port is positioned above the center of the wafer W, and the wafer W is rotated. By discharging the developer while holding the wafer W, the developer can be spread over the entire surface of the wafer W, and a puddle of the developer can be formed on the wafer W. FIG. Further, the puddle formation of the developer is performed by scanning a straight type nozzle over the wafer W in the same manner as the long nozzle, or by arranging a plurality of discharge ports for discharging the liquid on the wafer W like a straight type, and forming each discharge port. It may be carried out by supplying the developing solution from the

The spray nozzle 41 has a nozzle body 42 . The nozzle main body 42 is provided on a nozzle support portion (not shown) such as an arm, and the nozzle support portion is driven by a drive mechanism (not shown) in a reciprocating arrow C (Z direction) indicated by a dashed line in the drawing. , and can move horizontally as indicated by a reciprocating arrow D (X direction) indicated by a dashed line.

The spray nozzle 41 in the embodiment has a spray part 43 and a cleaning liquid supply nozzle 44 . Liquid and gas supplied from a supply source 45 of a liquid that does not promote development, such as water, and a supply source 46 of a gas used for spraying (for example, clean air, inert gas such as nitrogen gas) are separated from each other. The liquid is mixed in the mixing section 47 and supplied to the spray section 43 , and mist of the liquid is sprayed from the spray section 43 . A cleaning liquid is supplied to the cleaning liquid supply nozzle 44 from a cleaning liquid supply source 48 . The cleaning liquid supply nozzle 44 is used when cleaning the developer from the wafer W after development. As the gas used for spraying, an inert gas is more preferable so as not to inadvertently affect the liquid treatment.

The developing device 1 is controlled by a control device 100, which is a control section. The control device 100 is, for example, a computer equipped with a CPU, memory, etc., and has a program storage unit (not shown). Various programs for controlling the developing process of the wafer W in the developing device 1 are stored in the program storage unit. The program may be recorded in a computer-readable storage medium and installed in the control device 100 from the storage medium. The storage medium H may be a temporary storage medium or a non-temporary storage medium.

An example of control is a series of processes from development to washing and drying. For example, the movement of the developer nozzle 31 and the spray nozzle 41, the start and stop of the spray from the spray unit 43, the supply and stop of the cleaning liquid from the cleaning liquid supply nozzle 44, the rotation and stop of the spin chuck 11, a series of development processing, and further also controls the operation of the air blower 14, the liquid drainage device 25, the valve 26, and the exhaust device 27.

Next, a developing method using the developing device 1 having the above configuration will be described with reference to FIGS. 2(a) to 2(e). This developing method is an example in which a so-called long nozzle having a discharge port having a length equal to or longer than the diameter of the wafer W is used as the developer nozzle 31 . First, the wafer W held on the spin chuck 11 is horizontally scanned from one end to the other end while the developer nozzle 31 supplies the developer onto the wafer W (FIG. 2 ( a)). As a result, a puddle K of developer is formed on the wafer W, and the wafer W is statically developed (FIG. 2(b)). When the paddle K is formed, the developer nozzle 31 is retracted to the waiting position.

After that, as shown in FIG. 2(c), the spray nozzle 41 moves toward the center of the wafer W and stops at a predetermined position. The predetermined position in this case is a place where the spraying part 43 is positioned above the center of the wafer W. As shown in FIG.

Then, as shown in FIG. 2(d), water is sprayed from the spray unit 43 onto the paddle K on the wafer W as a liquid that does not promote development. When the water is sprayed, the water mist vaporizes just before reaching the paddle K, and the latent heat of vaporization at that time lowers the temperature of the surface of the paddle K (temperature control process). In this case, the spin chuck 11 may or may not be rotated. Details such as the timing and number of times of spraying will be described later.

After that, when the in-plane temperature control of the paddle K by the spray from the spray part 43 of the spray nozzle 41 is completed, the spray nozzle 41 moves and the center of the cleaning liquid supply nozzle 44 moves as shown in FIG. 2(e). Move over the center of the wafer W and stop. After that, while rotating the wafer W, the cleaning liquid F is supplied from the cleaning liquid supply nozzle 44 toward the center of the wafer W, so that the developer forming the puddle K is shaken off and the surface of the wafer W is cleaned with the cleaning liquid. Washed by F.

The developing process shown in FIG. 2 is an example in which the developer nozzle 31 is an elongated nozzle having a discharge port longer than the diameter of the wafer W. When a straight type nozzle is used, only the process of forming the paddle K at the beginning is different. That is, by supplying the developing solution toward the center of the wafer W while rotating the wafer W, the supplied developing solution is diffused over the entire surface of the wafer W by centrifugal force to form the paddle K. As shown in FIG. The process after paddle formation is the same as that shown in FIGS. 2(b) to 2(e). In this case, when discharging using a straight type nozzle as the developer nozzle 31, when the developer is supplied by arranging a plurality of discharge ports on the wafer W, at a position overlapping the developer nozzle 31, The plurality of ejection ports may be arranged and moved integrally like the developer nozzle 31 .

By the way, according to the knowledge of the inventors, regarding the in-plane temperature distribution of the paddle K, it has been found that the peripheral portion has a larger temperature drop than the central portion. FIG. 3 shows temperature changes at the central portion and the peripheral portion of the wafer W after the puddle K of the developer is formed. showing change. It is considered that the reason why the temperature drop in the peripheral portion is larger than that in the central portion is that the wafer W is exhausted from the outside of the peripheral portion. If the temperature drop in the peripheral portion is greater than that in the central portion, the uniformity of the developing process is affected, and the line width of the pattern after development becomes non-uniform.

Therefore, as shown in FIG. 4, for example, when the liquid is sprayed from the spray part 43 of the spray nozzle 41 toward the paddle 15 seconds after the formation of the paddle (S in the figure), the central portion of the wafer W 3, and the temperature difference T between the center and edge of the wafer W 60 seconds after the formation of the paddle is smaller than in FIG. As a result of actual measurement, the temperature difference T between the central part and the peripheral part after 60 seconds in FIG. The temperature difference T between the part and the peripheral part was about 0.5° C., which was less than half.

Thus, it was confirmed that the temperature of the center of the paddle K can be lowered by spraying the liquid conically from above the center of the surface of the paddle K after the formation of the paddle K. In the example described above, the total amount of spray was 2.5 ml. More specifically, FIG. 4 shows an example of spraying 25 times with a spray nozzle 41 that sprays 0.1 ml per time. The spray height (the height from the surface of the paddle K to the spray port of the spray section 43) was 150 mm. Considering the function of lowering the temperature of the paddle K on the surface of the wafer W by the heat of vaporization, it is preferable that the sprayed liquid mist is completely vaporized immediately before the surface of the paddle K. Therefore, the spray amount and the spray height Furthermore, it is preferable to determine the particle diameter of the sprayed mist from this point of view.

From this point of view, it is considered preferable that the spray amount is 0.1 ml to 0.5 ml per time, the spray height is 12 mm to 150 mm, and the particle size of the mist is, for example, 0.1 μm to 5.0 μm. Even if the spray height is relatively close to the substrate, for example, 12 mm, it is preferable that the sprayed liquid is sufficiently diffused radially and vaporized before reaching the wafer W or the paddle K.
Further, in the present embodiment, the liquid sprayed from the spray portion 43 of the spray nozzle 41 is a liquid that does not promote development. does not significantly affect the

As a result of further investigation, it was found that after formation of the puddle K, during the development process, spraying in the first half of the process was more temperature sensitive. Therefore, it is more suitable to control the temperature of the paddle K by spraying in the first half of the treatment.

Alternatively, the liquid sprayed from the spray portion 43 of the spray nozzle 41 may be sprayed with a diluted developer. As a result, even if the sprayed mist adheres to the paddle K, almost no change in the concentration of the developer is observed.
In the technique described in Patent Document 1, the temperature of the discharged air is adjusted by warming it. As long as there exists, the wafer W is hardly affected, and it is known that the temperature cannot be controlled. In this regard, the technique of the present disclosure sprays the easily vaporizable mist even after the puddle is formed. can. Moreover, in the technique of the present disclosure, the temperature is controlled while proceeding with development processing using a developer puddle. Of course, it is unnecessary to adjust the temperature of the liquid mist to be sprayed.

In the above example, the paddle K of the developer is formed on the surface of the wafer W, and then the paddle is sprayed. You may make it spray the above-described liquid. Further, the number of times of spraying is not limited to one time, but may be a plurality of times.

FIG. 5 shows temperature changes at the center and the periphery of the wafer W on which the paddle K is not formed, when the wafer W is sprayed once after 10 seconds have elapsed. It shows the temperature change at the periphery. In this case, the temperature of the peripheral portion is higher than the temperature of the central portion. Since the paddle K is not formed, the temperature of the wafer W is constant around the ambient temperature (usually 23° C.) in the apparatus. In this state, if the mist is sprayed from a position where the spray height is 75 mm, for example, there are places on the peripheral edge of the wafer W where the mist does not spread. It is from.

On the other hand, FIG. 6 shows temperature changes at the central portion and the peripheral portion of the wafer W when spraying is performed three times after 10 seconds have passed. In the figure, the thick line indicates the temperature change in the central portion, and the thin line indicates the temperature change in the peripheral portion. By spraying the wafer W a plurality of times in this manner, the temperature of both the central portion and the peripheral portion can be lowered more than in the case of the single spraying shown in FIG. However, since the mist is sprayed from above the center of the wafer W, the mist tends to gather in the central portion and form a liquid pool. Got. Further, since there is no processing liquid such as a developing liquid on the wafer W, by spraying pure water as the liquid, even if the pure water mist adheres to the wafer surface, subsequent development and the like will not be possible. It does not affect liquid processing.

In the above-described example, the spray part 43 of the spray nozzle 41 is positioned above the center of the wafer W to spray. However, as shown in FIG. You may make it spray from the upper part of a position. As described above, after the formation of the paddle K, the temperature drop at the peripheral edge of the wafer W is greater. It is preferable to spray an area including the center P of W.

Even in such a case, it is not always necessary to rotate the wafer W by driving the spin chuck 11, so that the temperature of a specific region of the paddle K can be lowered. For example, when the resist on the wafer W is an i-line resist, it is known that the lower the temperature, the more the development process proceeds. Therefore, the temperature of a specific area can be lowered to accelerate the development process. Using this, the following temperature control becomes possible. For example, when forming the puddle K of the developer, if the supply starts from one end of the wafer W, the development process progresses at the one end more than the other end at the end of the supply. In order to correct this, there is also a process of spraying the other end to lower the temperature from the one end, thereby promoting the development processing of the one end and catching up with the progress of the development processing of the other end. be possible.

From this point of view, as shown in FIG. 9, when spraying the wafer W held by the spin chuck 11 with the spraying part 43 of the spray nozzle 50 tilted, it is possible to spray from the center of the wafer W in the vertical direction. You may make it incline diagonally and make it spray. In such a case, the spin chuck 11 may or may not be rotated. That is, it may be appropriately selected in accordance with the area where the temperature is to be lowered.

Although the spray nozzle 41 described above has one spray part, it is not limited to this, and a spray nozzle 50 shown in FIG. 10 has a plurality of spray parts, for example, two spray parts 43a and 43b may be

That is, the spray nozzle 50 shown in FIG. 10 has a spray portion 43a that sprays the center portion of the wafer W and a spray portion 43b that sprays the peripheral portion of the wafer W. As shown in FIG. By using the spray nozzles having such a configuration, the control device 100 can control the spray parts 43a and 43b so that the central part of the surface of the wafer W is sprayed for a longer time than the peripheral part. As a result, it is possible to spray the central portion of the wafer W for a longer period of time so that the temperature drop is greater than that of the peripheral portion.

Furthermore, it is possible to spray only the central portion and stop the spraying to the peripheral portion, or to spray with a smaller amount than the central portion. As a result, temperature control for each region of the wafer W can be performed more finely by spraying.

In the above example, the flow velocity of the spray from the spraying part of the spray nozzle is not particularly explained, but after the formation of the paddle K, the development process is in progress, so the surface of the wafer W is not exposed by the spray. It is preferable to spray at such a flow rate. This is because when the surface is exposed, the development processing of the exposed portion is stopped.

The exhaust amount during spraying from the spray nozzles 41 and 50 is smaller than the exhaust amount when cleaning the wafer W after the liquid treatment. This is because there is no particular need to pay attention to the in-plane temperature of the wafer W after the liquid treatment, and on the other hand, since a large amount of mist of the cleaning liquid is generated during cleaning, it is necessary to quickly exhaust the mist. Also, during the spraying, it is possible to perform suitable temperature control by not disturbing the spray flow.

Further, the spray nozzle 41 described above has a configuration in which the spray portion 43 and the cleaning liquid supply nozzle 44 are integrated, but it may be configured separately from the cleaning liquid supply nozzle like the spray nozzle 50 .

Although the above example is particularly effective for development of i-line resist sensitive to temperature, the present disclosure is not limited to this, and exposure with energy rays such as g-line, KrF excimer laser, ArF excimer laser, etc. is also possible. It is also effective for resist development.

It should be considered that the embodiments disclosed this time are illustrative in all respects and not restrictive. The embodiments described above may be omitted, substituted, or modified in various ways without departing from the scope and spirit of the appended claims.

Reference Signs List 1 developing device 10 case 11 spin chuck 12 rotating part 13 rotary driving part 14 blower 21 cup 22 bottom 23 drain pipe 24 exhaust pipe 25 drain device 26 valve 27 exhaust device 31 developer nozzle 32 nozzle support 41, 50 Spray nozzle 42 Nozzle body 43, 43a, 43b Spray part 44 Cleaning liquid supply nozzle 100 Control device F Cleaning liquid K Paddle W Wafer

Claims (11)

A liquid processing apparatus that performs liquid processing with a processing liquid on a substrate,
a substrate holder that holds and rotates the substrate;
liquid processing, comprising a spray nozzle positioned above the substrate held by the substrate holding part and spraying a liquid that does not promote the liquid processing onto an in-plane area of the substrate including the center of the substrate; Device. Having a control unit that controls the spray nozzle,
The liquid processing is development processing, and the control unit is configured to spray the liquid from the spray nozzle during at least the first half of the development processing time with the developer after forming a puddle of the developer on the surface of the substrate. The liquid processing apparatus according to claim 1, wherein A liquid processing apparatus for developing a substrate by forming a puddle of a developer, which is a processing liquid, on a substrate,
a substrate holder that holds and rotates the substrate;
a spray nozzle positioned above the substrate held by the substrate holding part for spraying a liquid obtained by diluting the developer onto an in-plane area of the substrate including the center of the substrate;
a control unit that controls the spray nozzle;
A liquid processing apparatus. 4. The liquid processing apparatus according to claim 2, wherein the control unit is configured such that the spray nozzle sprays a plurality of times during development processing with the developer. Having a control unit that controls the spray nozzle,
The control unit is configured such that the spray nozzle sprays the liquid onto an in-plane region of the substrate including the center of the substrate before the processing liquid is supplied onto the substrate. 2. The liquid processing apparatus according to claim 1. The spray nozzle has a spray part that sprays the central part of the substrate and another spray part that sprays the peripheral part of the substrate,
6. The liquid processing apparatus according to any one of claims 2 to 5, wherein the control unit is configured to spray the central portion of the surface of the substrate for a longer time than the peripheral edge portion. The spray nozzle has a spray part that sprays the central part of the substrate and another spray part that sprays the peripheral part of the substrate,
6. The control unit according to any one of claims 2 to 5, wherein the control unit is configured so as to spray a central portion of the surface of the substrate while not spraying a peripheral portion of the surface of the substrate. The liquid processing apparatus described. When the processing liquid is sprayed toward the puddle of the processing liquid formed on the substrate on which the liquid processing is in progress on the surface of the substrate, the spraying is performed at a flow rate such that the surface of the substrate is not exposed by the spraying. The liquid processing apparatus according to any one of claims 2 to 7. further comprising an exhaust unit configured to exhaust an atmosphere around the substrate held by the substrate holding unit;
The control unit controls the exhaust unit so that an exhaust amount during spraying of the liquid from the spray nozzle is smaller than an exhaust amount during cleaning of the substrate after liquid processing of the substrate is completed. The liquid processing apparatus according to any one of claims 2 to 8, which is configured to control the 10. The spray nozzle according to any one of claims 1 to 9, wherein when spraying from the spray nozzle onto the substrate held by the substrate holding part, the spray is performed while being tilted obliquely from the vertical direction of the center of the substrate. Liquid processing equipment. A liquid processing method for liquid processing a substrate, comprising:
spraying a liquid from above a substrate holder that holds and rotates the substrate onto an in-plane region of the substrate including the center of the substrate;
A liquid processing method, wherein the temperature of the substrate or the processing liquid on the substrate is controlled by heat of vaporization of the sprayed liquid.

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