JP2003017387A - Method and apparatus for hmds processing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and an apparatus for HMDS processing which can reduce photoresist peeling. SOLUTION: The HMDS processing apparatus 1 is constituted by installing a vapor scattering part 30 which vaporizes HMDS vapor from liquid HMDS 101 in an HMDS processing chamber 10, and HMDS processing is performed by generating an HMDS processing atmosphere in the HMDS processing chamber by saturating the inside with the HMDS vapor.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an HMDS processing method and an HMDS processing apparatus for applying HMDS to a wafer before applying a photoresist to the wafer.

[0002]

2. Description of the Related Art Hexamethyldisilazane (HMD) is used to improve adhesion of a photoresist applied to a silicon single crystal wafer (hereinafter simply referred to as "wafer") in a semiconductor manufacturing process.
It is known to apply S) (hereinafter referred to as “HMDS treatment”).

FIG. 2 is a schematic diagram showing a conventionally known HMDS processing apparatus 100. In the HMDS processing apparatus 100, the wafer W is placed on the heating plate 106 in the HMDS processing chamber 105. The HMDS processing chamber 105 is designed to mount only one wafer W. Then, nitrogen gas is blown into the bottle 102 that stores the liquid HMDS 101 from the pipe 103 to cause bubbling to generate HMDS vapor. This HMDS vapor is jetted toward the wafer W together with nitrogen gas through the pipe 104 (hereinafter referred to as "bubbling method"). After the HMDS treatment, the wafer W is coated with a photoresist.

[0004]

However, the photoresist applied as described above may not adhere sufficiently to the wafer W, and the photoresist may peel off in the subsequent patterning step or etching step. is there.

An object of the present invention is to provide an HMDS processing method and an HMDS processing apparatus capable of reducing photoresist peeling.

[0006]

In order to solve the above problems, the inventors of the present invention have conducted extensive studies, and as a result, as a factor affecting the photoresist peeling, the concentration of HMDS vapor contained in the HMDS treatment atmosphere was changed. I paid attention. In the conventional bubbling method, since the HMDS processing chamber is opened every time the HMDS processing of one wafer is completed, the concentration of HMDS vapor is lowered in the HMDS processing chamber. Since the concentration of the HMDS vapor supplied into the HMDS treatment chamber by the bubbling method cannot be higher than the saturated state, it takes time to re-saturate the HMDS vapor in the opened HMDS treatment chamber. If the HMDS process is performed in the unsaturated state, the photoresist does not sufficiently adhere to the wafer. Therefore, by using an HMDS processing device capable of easily saturating the HMDS vapor and performing the HMDS processing in this processing atmosphere, it has been possible to significantly suppress the peeling of the photoresist.

That is, the HMDS processing method of the present invention is an HMDS processing method of applying HMDS to a wafer before applying a photoresist to the wafer.
It is characterized in that the HMDS treatment is performed in a treatment atmosphere in which S vapor is saturated.

Further, the HMDS treatment apparatus of the present invention is characterized by volatilizing HMDS vapor from liquid HMDS to produce H
It is characterized in that a vapor dissipating portion for forming an MDS processing atmosphere is provided inside the HMDS processing chamber which is hermetically disposed.

Here, the vapor dissipating portion is a container into which the liquid HMDS is injected, and the liquid HMDS injected into the container.
It may be configured by including a heating unit for volatilizing the.
In this case, the heating unit is the liquid HMD injected into the container.
A plate to be submerged in S, a flow passage for circulating a heat medium through the inside of the plate, and a temperature control device for controlling the heat medium to circulate at a constant temperature may be provided. .

Further, in the present invention, it is preferable that the HMDS processing chamber is provided with an installation portion for installing a support containing a plurality of wafers.

According to the present invention, the HMDS processing chamber is closed, and the liquid HMDS is heated inside the HMDS processing chamber to generate HMDS vapor. This HMDS vapor is H
Inside the MDS processing chamber, an HMDS processing atmosphere is formed which is filled with high concentration and is saturated with HMDS vapor. As a result, HMDS is sufficiently applied to the wafer surface, so that the adhesiveness of the photoresist can be secured. Also, HM
Since the HMDS vapor can be easily saturated in the DS processing chamber, it is possible to collectively process a plurality of wafers.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION An HMDS processing apparatus 1 according to an embodiment of the present invention will be described in detail below with reference to FIG. This HMDS processing device 1 is, as shown in FIG.
The processing chamber 10 and the HMDS container installation chamber 20 are arranged via a partition wall.

The HMDS processing chamber 10 is a room in which a processing atmosphere for performing the HMDS processing is formed, and as shown in FIG. 1, the interior thereof is divided into an upper space 11 and a lower space by a partition plate 13 arranged horizontally. It is partitioned into a space (installation section) 12. The partition plate 13 is provided with a large number of openings 16 so that the upper space 11 and the lower space 12 communicate with each other. A vapor dissipating portion 30 that dissipates HMDS vapor is disposed on the upper surface of the partition plate 13.

As shown in FIG. 1, the vapor dissipating section 30 includes a container 31 into which the liquid HMDS 101 is injected, and a heating section 32 for keeping the liquid HMDS 101 injected into the container 31 at a temperature at which the liquid HMDS 101 is volatilized. Prepare This heating unit 32
Comprises a plate 33 which is submerged in the liquid HMDS 101 in the container 31. The plate 33 has a hollow passage 33a formed therein. The hollow passage 33a goes from the inflow port 33b exposed on the surface of the plate 33 to the outflow port 33c exposed on the surface of the plate 33 again via the inside of the plate 33. One end of a wire hose 34 is connected to the inflow port 33b and the outflow port 33c. These wire hoses 34 are connected via a silicone rubber hose (not shown) to a temperature controller 36 having a constant temperature liquid bath 36a. Thus, the hollow passage 33a of the plate 33, the wire hose 34, and the silicone rubber hose constitute the flow passage 35 for circulating hot water (heat medium). Then, by circulating hot water in the hollow passage 33a of the plate 33, heat of the hot water is transferred to the liquid HMDS 101 via the plate 33, and is maintained at a predetermined temperature at which the liquid HMDS 101 is volatilized. The hot water circulated in the plate 33 is the temperature control device 36.
Is controlled to a constant temperature.

Further, the HMDS processing chamber 10 is provided with a thermometer 14 and a differential pressure gauge 15 on the front surface. The thermometer 14 is connected to the thermocouple 14a, and the thermocouple 1
4a has a tip inserted into the liquid HMDS 101 injected into the container 31. As a result, the thermometer 14 has a thermocouple 1
The temperature of the liquid HMDS 101 measured by 4a is displayed. On the other hand, the differential pressure gauge 15 is connected to a pressure sensor 15a provided so as to project inside the HMDS processing chamber 10, and the HMD measured by this pressure sensor 15a is measured.
The internal pressure of the S processing chamber 10 is displayed.

With this HMDS processing apparatus 1, the wafer W is HMDS processed as follows. First, HMD
The gallon bottle 2 containing the liquid HMDS 101 is installed in the S container installation chamber 20. Next, the support 3 on which a plurality of wafers W are vertically installed is installed in the lower space 12 of the HMDS processing chamber 10.

Next, the atmosphere in the HMDS processing chamber 10 is replaced with nitrogen. As shown in FIG. 1, when the main valve 41, which is a ball valve, is opened, the nitrogen gas supplied from the cylinder 40 is depressurized to a predetermined pressure by the depressurization valve 42, and is passed through the filter 44 to the HMDS processing chamber 10.
Is supplied to the space 11 above. The flow rate of the nitrogen gas is displayed by the area type flow meter 43.

Thereafter, the supply of nitrogen gas is stopped, the HMDS processing chamber 10 is closed, and a predetermined amount of liquid HMDS 101 is injected into the container 31 from the gallon bottle 2. As shown in FIG. 1, when the three-way valve 50 is opened, the nitrogen gas supplied from the cylinder 40 is depressurized to a predetermined pressure by the pressure reducing valve 47, and then the HMDS container installation chamber 20 via the relief valve 48 and the filter 49. Is supplied to. As a result, a stainless steel supply pipe 51 whose one end is inserted into the gallon bottle 2
The liquid HMDS 101 is pressure-fed via the. In this way, the liquid HMDS 101 in the gallon bottle 2 is poured into the container 31.

Then, under the control of a control unit (not shown), hot water controlled to a constant temperature by the constant temperature liquid tank 36a of the temperature control device 36 is circulated. The heat of this hot water is transmitted to the liquid HMDS 101 via the plate 33, and the boiling point (12) at which the liquid HMDS 101 in the container 31 volatilizes.
It is kept at a predetermined temperature of 5.5 ° C. or less. Thus container 3
The liquid HMDS 101 of No. 1 is heated to dissipate the HMDS vapor from the vapor dissipating portion 30. The HMDS vapor passes through the opening 16 of the partition plate 13 and reaches the lower space 12. Here, since the HMDS processing chamber 10 is closed, the HM
The DS vapor is immediately saturated and filled, and a part thereof is liquefied on the inner wall of the HMDS processing chamber 10. In this way, a processing atmosphere in which the HMDS vapor is evenly saturated is formed in the lower space 12.

The wafer W is placed in this processing atmosphere for a predetermined time. During this time, the HMDS vapor is liquefied on the surface of the wafer W. As described above, by forming the processing atmosphere in which the HMDS vapor is maintained in the saturated state, the HMDS is sufficiently applied to the wafer W.

[Example] A silicon single crystal wafer having a diameter of 100 mm was used.
The support 3 capable of mounting one sheet is installed in the lower space 12 of the HMDS processing chamber 10. Further, by using the four support members 3, 100 silicon single crystal wafers can be collectively processed at one time. In this embodiment, the liquid HMDS 101 is kept at about 70 ° C., the silicon single crystal wafer W is placed in the processing atmosphere for 10 minutes, and the HMDS processing is performed. With respect to the silicon single crystal wafer thus treated with HMDS, the adhesiveness of the photoresist is confirmed by the following procedure. (Procedure 1) A photoresist having a predetermined thickness is applied to a HMDS-treated silicon single crystal wafer by a spin coating method. (Procedure 2) The photoresist layer is exposed and developed to form a predetermined pattern (this patterning is the “first time”).
And). Then, it is visually observed whether peeling is observed in the patterned photoresist layer. (Procedure 3) The patterned photoresist layer is removed by sulfuric acid / hydrogen peroxide treatment. (Procedure 4) Procedures 1 to 3 after HMDS processing is performed again
The above steps are similarly performed to form a photoresist layer in a predetermined pattern (this patterning is referred to as "second time").
Then, it is visually observed whether the photoresist layer is peeled off. (Procedure 5) As described above, as the number of times the photoresist layer is applied and removed repeatedly on the same silicon wafer, the photoresist layer becomes difficult to adhere. Therefore, the same procedure is repeated thereafter to confirm whether the photoresist layer is peeled off.

When the photoresist layer repeatedly patterned by the above procedure was visually observed each time, no peeled portion was found in the photoresist layer patterned 20th time. An etching step, which is a post-step, is further performed on the silicon single crystal wafer patterned in the 20th time. In this case, if the adhesiveness of the photoresist layer is not sufficient, a phenomenon (hereinafter referred to as "undercut") in which the etching solution enters the gap between the silicon single crystal wafer and the photoresist layer and is removed by etching is observed. May be However, in the present example, the oxide film could be removed by etching in accordance with the patterning even in the 20th time. From the above, it was confirmed that the adhesion of the photoresist was secured by using the HMDS processing apparatus 1 of the present invention.

Also, in the following two cases using silicon single crystal wafers having different diameters, the adhesion of the photoresist could be confirmed in the same manner. (1) 25 silicon single crystal wafers with a diameter of 125 mm
Four braces capable of placing one sheet are installed in the HMDS processing chamber 10, and 100 sheets are collectively processed for HMDS. (2) 25 silicon single crystal wafers with a diameter of 150 mm
Two supports capable of mounting one sheet are installed in the HMDS processing chamber 10, and 50 sheets are collectively processed for HMDS.

[Comparative Example] HM by conventional bubbling method
Using a DS processor (shown in Fig. 2), diameter 100m
HMDS processing is performed on each of the silicon single crystal wafers of m. After that, the adhesion of the photoresist is confirmed by the same procedure as in this embodiment. As a result, a clearly peeled portion was found in the photoresist layer patterned for the third time. The peeling of this photoresist layer
It occurred in the development after exposure. When the third patterned silicon single crystal wafer was subjected to an etching treatment, a clear undercut was generated at a portion where the peeling of the photoresist layer was observed.

The present invention is not limited to the above embodiment. For example, although the photoresist layer is applied by the spin coating method in this embodiment, it may be applied by the spray coating method, the dip coating method, or the like. That is, it goes without saying that appropriate changes can be made without departing from the spirit of the present invention.

[0026]

According to the present invention, by performing the HMDS treatment in the HMDS treatment atmosphere in which the HMDS vapor is saturated, the HMDS is sufficiently coated on the wafer surface, so that the adhesion of the photoresist is ensured. The peeling of the photoresist can be reduced.

[Brief description of drawings]

FIG. 1 is a piping system diagram showing an HMDS processing apparatus 1 of an embodiment to which the present invention is applied.

FIG. 2 is a diagram showing a conventional HMDS processing apparatus 100.

[Explanation of symbols]

1 HMDS processor 3 Supports 10 HMDS processing room 12 Lower space (installation section) 30 Vapor dissipation part 31 containers 32 heating section 33 plates 35 flow passage 36 Temperature controller W wafer

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 2H025 AB16 DA35                 4D075 BB57Y BB69Y BB93Y CA13                       DA08 DB14 DC22 EA45 EB42                       EC07                 4F042 AA02 AA07 BA19 DA02 DA03                       DE01 DE07                 5F046 HA02

Claims (5)

[Claims] 1. A HMDS processing method of applying HMDS to a wafer before applying a photoresist to the wafer, the method comprising the steps of: HMDS in a processing atmosphere saturated with HMDS vapor.
An HMDS processing method characterized by performing processing. 2. A HMDS treatment chamber which is hermetically disposed, wherein a vapor dissipating portion for forming an HMDS treatment atmosphere by vaporizing HMDS vapor from liquid HMDS is provided inside the HMDS treatment chamber. Processing equipment. 3. The vapor dissipating portion is provided in the liquid HMDS.
And a liquid H injected into the container.
The HMDS processing device according to claim 2, further comprising a heating unit for volatilizing MDS. 4. The heating unit includes a plate submerged in the liquid HMDS poured into the container, a flow passage for circulating a heat medium through the inside of the plate, and a constant temperature of the heat medium. 4. A HMDS according to claim 3, further comprising:
Processing equipment. 5. The HMD according to any one of claims 2 to 4, wherein the HMDS processing chamber is provided with an installation unit for installing a support containing a plurality of wafers.
S processor.