JP2883874B2 - Substrate processing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a method for processing a substrate.

[0002]

2. Description of the Related Art In general, a heating apparatus is used in a heat treatment process for an object to be processed, for example, a heat treatment process for a semiconductor wafer or the like in semiconductor device manufacturing. For example, when a fine circuit pattern is transferred to a semiconductor wafer, a photolithography technique is used. In this photolithography process, a heating device is used, for example, for heating a semiconductor wafer coated with a photoresist. .

In such a heating apparatus, for example, a hot plate having a resistance heating heater is used as a heat source. Then, the semiconductor wafer is directly placed on a hot plate provided in the processing chamber or placed close to each other with a minute interval called a proximity gap or the like, and the semiconductor wafer is heated by conduction or radiation. .

Many of the above-mentioned hot plates are provided with a plurality of, for example, three pins for supporting a semiconductor wafer on the hot plate at the time of loading / unloading and transferring the semiconductor wafer to / from a transfer device or the like.

Further, the semiconductor wafer which has become high in temperature after the heat treatment is supported on these pins, and exhaust is performed in this state to form an air flow substantially parallel to the semiconductor wafer in the processing chamber. There is a heating device configured to cool a semiconductor wafer.

Further, at the time of the heat treatment, an inert gas such as a nitrogen gas is supplied to perform the treatment in an inert gas atmosphere.

[0007]

As described above, conventionally, an inert gas such as a nitrogen gas is supplied to process a substrate such as a semiconductor wafer in an inert gas atmosphere.

However, in the processing of such a substrate, there is a problem that the processing temperature of the substrate becomes inaccurate or non-uniform due to the supply of an inert gas such as nitrogen gas, and a desired uniform processing cannot be performed. there were.

The present invention has been made in view of such conventional circumstances, and has as its object to provide a substrate processing method capable of performing desired uniform processing at a predetermined uniform temperature.

[0010]

According to a first aspect of the present invention, there is provided a method of processing a substrate, comprising the steps of: opening an opening / closing mechanism provided in a processing chamber; and loading a processing target substrate into the processing chamber; A step of mounting on a mounting portion that is provided in the processing chamber and can be set to a predetermined temperature; and a process that closes the opening / closing mechanism and is provided around the substrate to be processed mounted on the mounting portion. toward the supply port upward supplying an inert gas, the substrate to be processed in the inert gas atmosphere, and a step of treating the predetermined temperature, the remains closed the opening and closing mechanism
The substrate to be processed is separated from the mounting portion above the mounting portion described above.
While holding it from above the processing chamber.
The outside of the heat insulating cover provided above the mounting section
Is passed through the air flow substantially parallel to the substrate to be processed.
It characterized the this <br/> and a step of cooling by applying to the substrate to be processed by.

According to a second aspect of the present invention, in the method of processing a substrate according to the first aspect, when the substrate to be processed is processed in the inert gas atmosphere, exhausting is performed from the processing chamber. It is characterized by.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the drawings according to embodiments of the present invention. As shown in FIGS. 1 and 2, the inside of the housing 1 is made of, for example, a substantially disk-shaped aluminum plate or the like, the surface of which is hard anodized, and the semiconductor wafer 2 is mounted on the aluminum plate. Hot plate 3 is provided.

The hot plate 3 can be set to a predetermined temperature, for example, about 200 to 350 ° C. by a heating means (not shown), for example, a resistance heating heater. In addition, the hot plate 3
It is configured to be able to move up and down by a lifting device (not shown).
Further, a plurality of, for example, three pins 4 are provided so as to penetrate the hot plate 3. By lowering the hot plate 3, these pins 4 are projected on the hot plate 3, and these pins 4 The semiconductor wafer 2 is supported.
It is configured such that an interval (not shown) for inserting a transfer arm or the like can be inserted between the heating plate 3 and the heating plate 3.

Around the hot plate 3, the hot plate 3
A shield cover 5 is provided so as to surround the periphery of the cover. The shield cover 5 is connected to an elevating device for elevating and lowering the hot plate 3, and is configured to be able to move up and down together with the hot plate 3. In addition, this shield cover
A drive mechanism (not shown) for changing the relative height between the heating plate 5 and the heating plate 3 so that the shield cover 5 can be arranged at a higher position than the heating plate 3 as described later. Is provided.

On the upper surface of the shield cover 5,
Many ventilation holes 6 are provided, and around the hot plate 3,
A plurality of nitrogen gas supply ports 7 for supplying an inert gas such as a nitrogen gas are provided.

Further, the inside of the housing 1 is located on the side of the loading / unloading port 8 of the housing 1 (front) and on the opposite side (rear).
Two rectangular pipe-shaped exhaust ducts 9 and 10 are provided so as to sandwich both sides of the shield cover 5. These exhaust ducts 9 and 10 are connected to an exhaust device (not shown).
Side exhaust ports 11 and 12 and resist mist exhaust ports 13 and 14 opened upward are provided. In addition, an exhaust duct 9 provided at the rear (the side not on the side of the loading / unloading port 8) has an upper exhaust port 1 opening upward.
5 are provided.

On the other hand, a heat insulating cover 16 is provided above the hot plate 3 so as to cover the upper portion of the hot plate 3. The heat insulating cover 16 has a hollow structure so as to provide a heat insulating chamber 17 (a space for heat insulating) therein, and has a plurality of ventilation holes 18 on the lower surface thereof. Further, the heat insulating cover 16 is provided with an exhaust pipe (not shown) for connecting the resist mist exhaust ports 13 and 14 of the exhaust ducts 9 and 10 to exhaust air from the heat insulating chamber 17.

The heat insulating cover 16 is supported on the ceiling of the housing 1 through a heat insulating member such as a ceramic spacer 19, for example, and is provided between the heat insulating cover 16 and the ceiling of the housing 1. Is provided with a shield plate 20 for suppressing convective heat from the heat insulating cover 16. A plurality of ventilation holes 21 are provided in the ceiling of the housing 1.

Next, the operation of the baking apparatus having the above configuration will be described.

The hot plate 3 is previously heated to a predetermined temperature, for example, 200 to 350.
The temperature is set to about ° C., and the hot plate 3 and the shield cover 5 are lowered so that the pins 4 protrude above the hot plate 3 as shown in FIG. Then, in this state, the semiconductor wafer 2 is carried in from the carry-in / carry-out port 8 by a carrying device, for example, and placed on the pins 4.

Thereafter, as shown in FIG. 3, the hot plate 3 and the shield cover 5 are raised, the semiconductor wafer 2 is transferred from the pins 4 onto the hot plate 3, and the hot plate 3 and the shield cover are moved. A semi-hermetic processing space is formed between 5 and the heat insulating cover 16. At this time, a pin having a minute height may be provided on the hot plate 3 and a minute gap (proximity gap) may be provided between the hot plate 3 and the semiconductor wafer 2.

In this state, the semiconductor wafer 2 is heated for a predetermined time. During the processing, nitrogen gas is blown into the processing space from the nitrogen gas supply port 7 provided in the shield cover 5 as an inert gas. Thus, the semiconductor wafer 2 is placed in an inert gas atmosphere. At this time, the nitrogen gas is supplied from a plurality of nitrogen gas supply ports 7 provided so as to surround the periphery of the semiconductor wafer 2, so that the nitrogen gas flows upward and from the entire periphery of the semiconductor wafer 2. Since the nitrogen gas flows so as to diffuse toward the center of the semiconductor wafer 2, the low-temperature nitrogen gas immediately after flowing out from the nitrogen gas supply port 7 does not directly contact the semiconductor wafer 2, and the nitrogen gas It is uniformly supplied onto the semiconductor wafer 2 from the entire periphery.

Thus, the semiconductor wafer 2 is obtained. It is possible to prevent a situation such as partial cooling by the nitrogen gas flow, and it is possible to perform uniform processing at a predetermined temperature.

At this time, air is exhausted through exhaust ducts 9 and 10 by an exhaust device (not shown).

That is, in this state (the state in which the hot plate 3 and the shield cover 5 are raised), the exhaust ducts 9, 10
The lower exhaust ports 11 and 12 provided in the exhaust duct 9 are opened, while the upper exhaust port 15 provided in the exhaust duct 9 is closed.
Therefore, clean air is taken in from the vent 21 provided in the ceiling portion of the housing 1, and the clean air passes through the vent 6, lower exhaust ports 11, 12 of the shield cover 5 and the exhaust ducts 9, 10. An air flow is formed so as to flow into the inside, and heat storage in the housing 1 is prevented by the air flow. At this time, the resist mist and excess nitrogen gas generated from the semiconductor wafer 2 are removed from the heat insulating chamber 17 by an exhaust pipe (not shown) and the exhaust ports 13 and 14 for the resist mist, and the exhaust ducts 9 and 1.
Discharged through zero.

When the heat treatment for a predetermined time is completed, as shown in FIG. 4, the hot plate 3 and the shield cover 5 are removed.
To move the semiconductor wafer 2 onto the pins 4 and raise the shield cover 5 with respect to the hot plate 3,
The upper surface of the lid cover 5 is set to be substantially the same height as the semiconductor wafer 2, and the apparatus stands by in this state.

At this time, as the shield cover 5 is lowered, the lower exhaust ports 11 and 12 are closed, and the upper exhaust port 15 is opened. For this reason, the clean air flow accompanying the exhaust is, as shown by an arrow in FIG.
From 1, it is changed so as to pass between the semiconductor wafer 2 and the shield cover 5 and the heat insulating cover 16 and to flow into the exhaust duct 9 from the upper exhaust port 15. Therefore, the semiconductor wafer 2 heated to a high temperature by the clean air flow can be quickly cooled. Further, since this is shielded by the shield cover 5, this clean air flow does not hit the hot plate 3. Therefore, it is possible to prevent the heating plate 3 from being cooled as in the related art, and to prevent a temperature drop or a temperature gradient from occurring.

Thereafter, for example, when an arm of a transfer device for unloading the processed semiconductor wafer 2 moves forward of the loading / unloading port 8, the shield cover 5 is lowered, The loading / unloading port 8 is opened, the state is the same as the state shown in FIG. 1, the semiconductor wafer 2 is unloaded, and the processing of one semiconductor wafer 2 is completed.

That is, in the baking apparatus of this embodiment, the air flow for cooling the processed semiconductor wafer 2 by air is shielded by the shield cover 5 to prevent the hot plate 3 from being cooled. It prevents a temperature drop or a temperature gradient from occurring in the hot plate 3. Therefore, uniform heat treatment can always be performed at a predetermined temperature.

In the above embodiment, an example in which the present invention is applied to the baking of a semiconductor wafer has been described. However, the present invention is not limited to such an embodiment, and is intended to heat the object to be processed. If there is any, it can be applied.

[0031]

As described above, according to the substrate processing method of the present invention, a desired uniform processing can be performed at a predetermined uniform temperature.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a baking device used in one embodiment of the present invention.

FIG. 2 is a view showing a hot plate portion of the baking apparatus of FIG. 1;

FIG. 3 is a diagram showing a state during processing of the baking apparatus of FIG. 1;

FIG. 4 is a view showing a state in which the baking device of FIG. 1 is cooled.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Housing | casing 2 ... Semiconductor wafer 3 ... Hot plate 4 ... Pin 5 ... Shield cover 6 ... Vent 7 ... Nitrogen gas supply port 8 ... Loading / unloading 9, 10 ... Exhaust duct 11, 12 Lower exhaust port 13, 14 Exhaust port for resist mist 15 Upper exhaust port 16 Insulated cover 17 Insulated chamber 18 Vent 19 Ceramic spacer 20 …… Shield plate 21 …… Vent

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) H01L 21/027 B05C 9/14 G03F 7/38 501

Claims (2)

(57) [Claims] 1. An opening / closing mechanism provided in a processing chamber is opened,
A step of loading the substrate to be processed into the processing chamber; a step of mounting the substrate to be mounted on the mounting part provided in the processing chamber and capable of setting a predetermined temperature; and closing the opening / closing mechanism. An inert gas is supplied upward from a plurality of supply ports provided around the substrate to be processed placed on the mounting portion, and the substrate to be processed is placed in the inert gas atmosphere at the predetermined temperature. And placing the substrate to be processed with the opening and closing mechanism closed.
To be supported above the part in a state separated from the mounting part.
First, take in from above the processing chamber, and
Air that has passed through the outside of the heat-insulating cover
As an air flow substantially parallel to the substrate to be processed,
Method of processing a substrate, characterized by a step of cooling against. 2. The substrate processing method according to claim 1, wherein when the substrate to be processed is processed in the inert gas atmosphere, the substrate is evacuated from the processing chamber.