JP2002252155A - System and method for charged particle beam - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a system having improved throughput by reducing the time for waiting the stabilization of a sample size caused by cooling of atmosphere gas, due to adiabatic expansion in a load lock chamber. SOLUTION: The temperature of a treatment chamber is set lower than the ambient temperature of charged particle beams, corresponding to the sample temperature to be carried. As a result, treatment can be started, immediately after carrying the sample into the treatment chamber, and thereby throughput is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electron beam exposure apparatus used for lithography of semiconductor integrated circuits, an exposure apparatus using a charged particle beam such as an ion beam exposure apparatus, an inspection apparatus, and a measuring apparatus. It is concerned with the manufacturing method, inspection method, and measurement method using those devices and equipment. In particular, the present invention relates to an exposure apparatus that performs exposure under vacuum and is suitable for performing lithography with high throughput and high accuracy, and a manufacturing method.

[0002]

2. Description of the Related Art Conventionally, there is a system called a batch system for manufacturing, inspecting, and measuring a semiconductor or the like in a vacuum. In this method, a sample is directly loaded into the processing chamber from the atmosphere, the air in the processing chamber is exhausted after the loading, and a predetermined process is performed after heating the sample to compensate for a temperature drop due to adiabatic expansion that occurs at that time. Things. However, in this method, every time the sample is exchanged, the processing chamber needs to be changed from the atmospheric pressure to a vacuum state, and it takes a long time to evacuate. Further, in order to precisely control the temperature conditions in the processing chamber, it is necessary to control the temperature over a long time to bring the temperature of the sample to a predetermined temperature. As a result, there is a disadvantage that the processing efficiency is very low.

For this reason, in recent years, instead of directly loading a sample into a processing chamber, the sample is first loaded into a load lock chamber maintained at atmospheric pressure, and air in the load lock chamber is evacuated to a vacuum state. In general, a method of carrying a sample into a sample chamber in a vacuum state has been widely adopted.

[0004]

In a conventional apparatus having a load lock chamber, when the load lock chamber is evacuated while the sample is being carried into the load lock chamber, adiabatic expansion that occurs when the pressure is reduced. For this purpose, the atmosphere gas in the load lock chamber is cooled, and the cooled gas cools the sample and lowers the temperature of the sample. This temperature drop depends on conditions such as the volume of the load lock chamber, the heat capacity, the heat capacity of the sample, and the like. For example, in the case of a normally used load lock chamber having a capacity of several tens of liters, the temperature drops by 2 to 3 ° C. Due to this temperature decrease, the dimensions of the sample shrink.

When an 8-inch Si wafer is used, 1
Since a temperature change of ° C. causes a dimensional change of 0.5 μm,
A temperature drop of 3 ° C. causes a shrinkage of the sample dimensions of 1 μm or more.
This is, for example, a dimensional change that is a problem for an exposure apparatus, an inspection apparatus, or a measurement apparatus for a large-scale integrated circuit, and cannot satisfy the required accuracy required for manufacturing.

[0006] When the sample, whose dimensions have shrunk due to the temperature drop, is transported into the processing chamber, it is placed in an atmosphere at the processing temperature, which is then heated, and the sample begins to thermally expand. The exposure in the processing chamber is performed after the thermal expansion of the sample is stopped and the sample temperature and the sample size are stabilized over the entire surface of the sample. This waiting time is required when performing highly accurate exposure.
Especially long. For example, when an 8-inch Si wafer is used in a charged particle exposure apparatus, it is necessary to suppress a dimensional change to 10 nm or less.
It is necessary to keep the temperature difference below. In order to satisfy the temperature difference of 0.02 ° C. or less, the conventional apparatus requires several tens of minutes of waiting time, and this waiting time causes a problem of lowering the throughput.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems peculiar to the apparatus using the load lock chamber, and waits for the stability of the sample size due to the cooling of the atmosphere gas due to the adiabatic expansion in the load lock chamber. It is intended to provide a device that reduces time and improves throughput. It is another object of the present invention to provide an excellent manufacturing method, inspection method, and measurement method using this device.

[0008]

In order to improve the throughput of a load lock type vacuum processing apparatus, the present invention firstly comprises a load lock chamber and a processing chamber for maintaining a vacuum state.
In a charged particle beam apparatus that performs a predetermined process on a sample in the processing chamber, the temperature of the processing chamber is set to a temperature lower than the temperature around the charged particle beam apparatus in accordance with the temperature of the sample transferred to the processing chamber. A charged particle beam device characterized by having been set. (Claim 1) "is provided.

Thus, the waiting time in the processing chamber is reduced, and the throughput is improved. The second aspect of the present invention is that the low temperature setting of the processing chamber estimates a temperature decrease due to adiabatic expansion of the load lock chamber. Item 2) "is provided.

The charged particle exposure apparatus according to claim 1, wherein the sample is a sample for manufacturing a semiconductor, and the charged particle beam is an electron beam. (Claim 3) "is provided. As a result, a semiconductor can be manufactured with high throughput.

In the present invention, fourthly, the "charged particle beam device according to any one of claims 1 to 3, wherein the temperature around the charged particle beam device is a temperature flowing in a temperature control pipe outside the load lock chamber. Wire device. (Claim 4). Further, in the present invention, fifthly, in the semiconductor exposure method using the load lock chamber and the processing chamber that maintains a vacuum state, the temperature of the processing chamber is lower than the temperature around the load lock chamber in accordance with the temperature of the transferred sample. A semiconductor exposure method wherein the temperature is set (claim 5). Thereby, the waiting time in the processing chamber is reduced, and the throughput is improved.

In the sixth aspect of the present invention, there is provided an inspection light method using a load lock chamber and a processing chamber for maintaining a vacuum state, wherein the temperature of the processing chamber is adjusted to the temperature of the sample to be conveyed. Inspection method characterized in that the temperature is set lower than (6). Thereby, the waiting time in the processing chamber is reduced, and the inspection efficiency is improved.

[0013] In the present invention, a seventh aspect is a measuring method using a load lock chamber and a processing chamber for maintaining a vacuum state. A measurement method characterized by setting a low temperature. This allows
The waiting time in the processing room is reduced, and the measurement efficiency is improved.

In the present invention, an eighth aspect is that the low temperature setting of the processing chamber estimates a temperature drop due to adiabatic expansion of the load lock chamber.
4. The semiconductor exposure method according to 1. (Claim 8) "is provided.
Further, in the present invention, a ninth aspect is that the inspection method according to claim 6, wherein the low temperature setting of the processing chamber estimates a temperature decrease due to adiabatic expansion of the load lock chamber. 9) ”.

In the present invention, a tenth aspect is that the low temperature setting of the processing chamber is an estimation of a temperature drop due to adiabatic expansion of the load lock chamber.
Measurement method described in 1. (Claim 10) "is provided.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a load lock type vacuum processing apparatus according to the present invention will be described with reference to an electron beam exposure apparatus and method. FIG. 1 shows the structure of an electron beam exposure apparatus according to the present invention. The electron beam exposure apparatus includes an exposure unit main body 1, a load lock chamber 3, and an atmosphere chamber 8.

The pressure inside the atmosphere chamber 8 is always kept at the atmospheric pressure, and a plurality of samples 6 are stored in a sample carrier 7. The temperature is always kept in a constant environment. A metal holder 11 is arranged inside the load lock chamber 3. The holder temperature control pipe 10 is incorporated in the holder 11, and the temperature of the holder 11 is controlled by a fluid whose temperature is controlled in the holder temperature control pipe 10. On the upper surface of the holder 11, a holder table A4 is arranged so as to be in contact with the holder 11. For this reason, the holder table A4 is also controlled so that the temperature becomes a predetermined value by the heat conduction from the holder 11.

A temperature control pipe 1 is provided around the load lock chamber 3.
2 is arranged in contact with the outer wall, and the temperature of the load lock chamber 3 can be controlled by flowing a fluid whose temperature is controlled. Further, a robot arm (not shown) is disposed in the load lock chamber 3, and the load lock chamber 3
The sample 6 can be transported between the processing chamber 1a and the processing chamber 1a. The robot arm (not shown) can transfer the sample 6 between the atmosphere chamber 8 and the load lock chamber 3.

A valve 5 is attached to one end of the load lock chamber 3, and when the valve 5 is opened, a partition wall with the atmosphere chamber 8 moves to integrate the internal space. Further, when the valve 5 is closed, it is isolated from the atmosphere chamber 8 so that it can be a separate space.

An electron beam lens section 14 is provided above the exposure section main body 1, and a processing chamber 1a always kept in a vacuum is disposed below the electron beam lens section 14. The sample 6 is placed in the processing chamber 1a.
Is placed on the holder table B9. A holder table temperature control pipe 9a is embedded in the holder table B9, and the temperature of the holder table 9a can be controlled by flowing a temperature-controlled fluid.

The lower surface 14a of the electron beam lens unit incorporates a temperature control pipe 13 for the lower surface of the electron lens unit.
Temperature can be controlled. A temperature control pipe 12 is arranged around the exposure unit main body 1 in contact with the outer wall, and the temperature of the exposure unit main unit 1 can be controlled by flowing a fluid whose temperature is controlled. Exposure unit body 1
The valve 2 is disposed at one end, and the internal space of the load lock chamber 3 can be integrated by opening the valve 2. If the valve 2 is closed, the load lock chamber 3
And can be a separate space.

Next, the temperature of each part will be described. Outside the load lock chamber 3, a temperature control pipe 12 is arranged so as to be in contact with the load lock chamber 3, and the inside thereof is maintained at an ambient temperature where the electron beam exposure apparatus is placed, that is, usually at 23 ° C. which is an installation environment temperature. Since the dripped fluid flows, the temperature is kept almost constant. Further, the temperature control pipe for the holder buried inside the holder 11 is similarly maintained at the installation environment temperature. Similarly, on the outer surface of the exposure unit main body 1,
A temperature control pipe 12 is installed, and a fluid maintained at 23 ° C., which is an installation environment temperature, flows through the pipe, so that the temperature is maintained at a substantially constant temperature.

On the other hand, the temperature control pipe 9 for the holder table
a, A fluid having a temperature slightly lower than the installation environment temperature is supplied to the temperature control pipe 13 for the lower surface of the electron beam lens unit. This temperature difference allows for a temperature drop caused by reducing the pressure in the load lock chamber 3.

Next, the transport of the sample will be described with reference to FIG. In the initial state, the plurality of samples 6 are stored in the atmosphere chamber 8 while being stored in the sample carrier 7.
In this state, the plurality of samples 6 are kept at the environment set temperature. The valve 2 is closed, and the exposure unit main body 1 is kept in a vacuum state. On the other hand, the valve 5 is open, and the load lock chamber 3 is in a state where atmospheric pressure is applied.

The sample 6 placed in the atmosphere chamber 8 is transferred to the processing chamber 1a.
First, one of the samples 6 stored in the carrier 7 is transferred to the position B via the position C by a robot arm (not shown) installed in the load lock chamber 3.
Next, the valve 5 is closed, and the air in the load lock chamber 3 is exhausted by a vacuum pump (not shown) to be in a vacuum state. At this time, the temperature in the load lock chamber 3 decreases due to adiabatic expansion. The temperature of the sample 6 placed in the load lock chamber 3 is a temperature at the time when the sample 6 is initially left in the atmosphere chamber 8, but is gradually cooled by adiabatic expansion.

When the load lock chamber 8 reaches a vacuum, the valve 2 is opened, and is transferred from the position B to the position A by a robot arm (not shown) provided in the load lock chamber 3.
The position A is a predetermined position on the holder table B9, and the sample 6 is fixed at this position.

The temperature of the transported sample 6 is slightly lower than the installation environment temperature of about 23 ° C. due to adiabatic expansion in the load lock chamber 3. On the other hand, the temperature control pipe 9a for the holder table and the temperature control pipe 13 for the electron beam lens part are set to be lower in consideration of the temperature drop due to adiabatic expansion. Therefore, since there is no occurrence of a temperature difference with the sample 6, the waiting time for eliminating the temperature difference is short, and the exposure is performed immediately after the loading.

While the sample 6 is being exposed, the next sample 6
Are carried to the position B in the same procedure. When the exposure in the vacuum chamber 1a is completed, the valve 2 is opened, and the sample 6 is placed in a robot arm (not shown) provided in the load lock chamber 3.
Is carried from the position A to the position E. At this time valve 5
Is closed, and the load lock chamber 3 is in a vacuum state. At the same time, the next sample 6 waiting at position B
Is also immediately transported to the position A, the valve 2 is closed, and then the exposure is performed. During exposure, the sample 6 in which the valve 5 is open and in the E position is returned from the E position to the D position via the F position by a robot arm (not shown) provided in the load lock chamber 3. Then, the next sample 6 is similarly carried from the position D to the position B via the position C. Thus, the loading and unloading of the sample 6 are repeatedly performed.

In the above embodiment, the case where the present invention is applied to an electron beam exposure apparatus has been described. However, the present invention is basically applicable to all apparatuses using a load lock chamber. Therefore, it is needless to say that the present invention can be applied to other types of exposure apparatus such as an ion beam exposure apparatus, an inspection apparatus using an electron beam, and a measurement apparatus such as an electron microscope.

[0030]

As described above, according to the present invention, in the load lock type vacuum processing apparatus, the sample temperature is stabilized after the sample is transported and mounted on the sample stage in the processing chamber.
Since the time required for obtaining a uniform temperature distribution can be greatly reduced, the throughput of the load-lock type vacuum processing apparatus can be greatly increased, and the semiconductor process, exposure, inspection and measurement can be performed with high accuracy.

[Brief description of the drawings]

FIG. 1 is a view showing the structure of a load lock chamber vacuum processing apparatus according to the present invention.

FIG. 2 is a diagram showing an example of a sample transfer sequence in a vacuum processing apparatus of a load lock chamber.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Exposure part main body 1a Processing chamber 2 valve 3 Load lock chamber 4 Holder table A 5 Valve 6 Sample 7 Sample carrier 8 Atmosphere chamber 9 Holder table B 9a Temperature control pipe for holder table 10 Temperature control pipe for holder 11 Holder 12 Temperature control pipe 13 Temperature control pipe for lower surface of electron lens unit 14 Electron beam lens unit 14a Lower surface of electron beam lens unit

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01L 21/68 H01L 21/30 541L

Claims (10)

[Claims] 1. A charged particle beam apparatus comprising a load lock chamber and a processing chamber for maintaining a vacuum state, and performing a predetermined process on a sample in the processing chamber, wherein the temperature of the processing chamber is transferred to the processing chamber. A charged particle beam device, wherein the temperature is set lower than the temperature around the charged particle beam device according to the temperature of the sample. 2. The charged particle beam apparatus according to claim 1, wherein the low temperature setting of the processing chamber estimates a temperature drop due to adiabatic expansion of the load lock chamber. 3. The charged particle device according to claim 1, wherein the sample is a sample for manufacturing a semiconductor, the charged particle beam is an electron beam, and the predetermined processing is exposure. . 4. The charged particle beam apparatus according to claim 1, wherein the temperature around the charged particle beam apparatus is a temperature flowing in a temperature control pipe outside the load lock chamber. 5. A semiconductor exposure method using a load lock chamber and a processing chamber for maintaining a vacuum state, wherein the temperature of the processing chamber is set lower than the temperature around the load lock chamber in accordance with the temperature of a sample to be conveyed. A semiconductor exposure method, comprising: 6. An inspection method using a load lock chamber and a processing chamber that maintains a vacuum state, wherein the temperature of the processing chamber is set lower than the temperature around the load lock chamber in accordance with the temperature of a sample to be conveyed. An inspection method characterized by the following. 7. A measurement method using a load lock chamber and a processing chamber for maintaining a vacuum state, wherein the temperature of the processing chamber is set lower than the temperature around the load lock chamber in accordance with the temperature of a sample to be conveyed. A measuring method characterized by the following. 8. The semiconductor exposure method according to claim 5, wherein the low temperature setting of the processing chamber estimates a temperature drop due to adiabatic expansion of the load lock chamber. 9. The inspection method according to claim 6, wherein the low temperature setting of the processing chamber estimates a temperature drop due to adiabatic expansion of the load lock chamber. 10. The method according to claim 7, wherein the low temperature setting of the processing chamber estimates a temperature drop due to adiabatic expansion of the load lock chamber.