JPH1092724A - Load lock chamber - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent dust particles remaining within a load lock chamber from being blown up and deposited on the surface of a sample by providing a dustproof cover for covering the sample which is inside of the load lock chamber set between a vacuum device and outside with an ambient atmosphere and adapted for transporting the sample to and from the vacuum device. SOLUTION: Vacuum exhaust or leakage of a load lock chamber 33 is carried out. A sample stage 37 is raised. At this point, the sample stage 37 and a wafer 7 have their upper surfaces, lateral surfaces and lower surfaces covered with dustproof covers 35, 41. Only a slight gap is opened between a lower edge of a side plate 35b of the upper and side cover 35 and an outer peripheral edge of the lower cover 41. The dustproof covers 35, 41 themselves are made of aluminum or steel with inner surfaces thereof polished to be mirror finished surfaces, and these dustproof covers are detachable. Thus, the dustproof covers may be kept clean by periodical cleaning or replacement.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a load lock chamber for loading and unloading a sample for use in a semiconductor charged beam (EB or the like) exposure apparatus or a process apparatus for exposing a sample under vacuum, or an inspection apparatus. In particular, the present invention relates to a load lock chamber which has been improved so that dust remaining in the load lock chamber does not fly on the sample surface when exhausting and injecting air (also referred to as leakage) in the load lock chamber.

[0002]

2. Description of the Related Art Many processes for manufacturing and inspecting a semiconductor using a charged beam or the like are performed in a vacuum. In this case, it is rare that the sample in the atmosphere is directly carried into the vacuum device or the inside of the vacuum device is evacuated every time the sample is replaced. In most cases, the vacuum is always in a vacuum state,
When loading the sample, the sample is once put into the atmospheric load lock chamber, the load lock chamber is evacuated to a vacuum state from the atmosphere, and then the load lock chamber and the vacuum device are connected. Thereafter, a method of carrying a sample into a device in a vacuum state is adopted.

[0003]

In the process of evacuating and leaking while a sample is in a load lock chamber,
There is a problem that fine dust particles such as dust and dust adhere to the sample surface and become contaminated. This is because dust particles accumulated on the floor and walls of the load lock chamber soar up due to the flow of gas inside the chamber when the chamber is evacuated or leaked, and adhere to the sample. In order to prevent the dust particles from rising, exhausting and leaking are performed slowly over time during vacuum evacuation and leaking so as to suppress the flow of gas, so that there is a problem that throughput is reduced.

The present invention has been made in order to solve such a problem, and is directed to a load lock chamber for carrying a sample into and out of a vacuum apparatus, and when the chamber is evacuated and insufflated (also referred to as a leak), the chamber is closed. It is an object of the present invention to provide a load lock chamber improved so that dust remaining on the sample does not fly on the sample surface. It is another object of the present invention to provide a load lock chamber that can contribute to the realization of a vacuum device with high yield and high throughput.

[0005]

In order to solve the above-mentioned problems, a load lock chamber of the present invention is provided between a vacuum device for processing a sample under vacuum and the outside of the atmosphere, and the sample is placed in the vacuum device. A load lock chamber for carrying in and out, wherein a dustproof cover for covering the sample is provided in the chamber.

[0006]

FIG. 1 is an overall view of a semiconductor wafer electron beam exposure apparatus including a load lock chamber according to one embodiment of the present invention. FIG. 2 is a diagram showing details of the load lock chamber of FIG. 1 in a state where a wafer is carried in and out.

In the exposure apparatus shown in FIG. 1, a vacuum apparatus main body 1, a load lock chamber 3, and an atmosphere chamber 5 are connected in series.

In this case, the vacuum apparatus main body 1 is an exposure apparatus for a semiconductor wafer, and includes a charged beam exposure apparatus 11 and a sample chamber 13. In the sample chamber 13, a stage 15 on which the wafer 7a is mounted and travels on the X and Y axes is placed. A vacuum exhaust port 17 is opened at a lower portion of the sample chamber 13, and the inside of the sample chamber 13 is evacuated from the port 17 by a vacuum pump 21 via a valve 19. The degree of vacuum in the sample chamber 13 is, for example, 10 −6 Torr.

A load lock chamber 3 is connected to the vacuum apparatus main body 1 via a gate valve 2. The load lock chamber 3 includes a load lock chamber main body 31 that is a vacuum container. The sample stage 3 on which the wafer 7b is placed is placed in the load lock chamber main body 31.
7 is placed. The table 37 is of an elevating type (see FIGS. 2 and 3). Above the sample table 37, an upper / side cover 35
Is provided. The upper / side cover 35 is provided with a sample table 37.
And a cylindrical side plate 35b hanging down from the periphery of the top plate 35a. Below the sample table 37, a lower cover 41 that protrudes outward in a disk shape is provided.

On the side surface of the sample table 37, a leak port 39 is opened. The leak port 39 communicates with a leak pipe 43 formed in the base 37, and is connected to a leak gas source (not shown, an N2 cylinder or the like) via a valve 45. A vacuum exhaust port 47 is opened at the lower part of the load lock chamber main body 31, and the load lock chamber 33 is evacuated from the port 47 by a vacuum pump 49 via a valve 48. The degree of vacuum after evacuation of the load lock chamber 33 reaches 10-5 Torr as an example.

An atmosphere chamber 51 is connected to the load lock chamber main body 31 through a gate valve 4. In the atmosphere chamber 51, a carrier 53 on which the wafer 7c is placed is placed.

The operation of the load lock chamber 3 is shown in FIGS.
This will be described with reference to FIG. FIG. 2 shows the loading / unloading state of the wafer 7, and shows the sample table 37 in the load lock chamber 3.
Is falling down. The lower cover 41 attached to the side edge of the base 37 is also lowered. Top / side cover 3
5 is fixed to the upper part of the load lock chamber main body 31. Therefore, a sufficient space is provided between the lower end of the upper / side cover 35 and the upper surface of the sample table 37. At this interval, the arm 7 carries in the wafer 7 from the right side of the figure. Thereafter, the table 37 is raised to receive the wafer 7, and the arm 61 is retracted outside the load lock chamber main body 31.

FIG. 3 shows a state where the load lock chamber 33 is evacuated or leaked, and the sample table 37 is raised. At this time, the upper surface, side surfaces, and lower surface of the sample table 37 and the wafer 7 are covered with the dustproof covers 35 and 41. A slight gap 36 is formed between the lower edge of the side plate 35 b of the upper / side cover 35 and the outer edge of the lower cover 41.
(For example, about 1 mm) is only open.

When vacuum evacuation is performed in the state shown in FIG.
The atmosphere of No. 3 is exhausted from the lower vacuum exhaust port 47 to the outside of the load lock chamber. At this time, the air inside the cover 33b flows out of the cover 33a through the gap 36 between the upper and lower covers,
Thereafter, the air is exhausted from the vacuum exhaust port. When a leak (introduction of outside air) occurs, a leak gas (N2) is supplied to the inside 33b of the cover from the leak port 39 of the inside 33b of the cover, and exits outside the cover 33a through the gap 36 between the covers. What is important is that the direction of the air flow in both the case of evacuation and the case of a leak is the direction from the inside 33b of the cover to the outside 33a of the cover. Therefore, the dust particles remaining on the ceiling or bottom of the load lock chamber 33 do not soar by the airflow and enter the inside 33b of the cover.

The dust cover itself is made of aluminum or copper (an example) whose inner surface is mirror-polished, and is removable. Therefore, it can be kept clean by washing or replacing it regularly. In addition, because it is mirror polished, it can be made extremely clean by washing,
The cover itself rarely causes dirt.

[0016]

As is apparent from the above description, according to the present invention, since the dust-proof cover is provided in the load lock chamber, dust particles are contained in the semiconductor sample carried into and out of the load lock chamber without lowering the throughput. The problem of contamination caused by adhesion can be effectively solved.

[Brief description of the drawings]

FIG. 1 is an overall view of a semiconductor wafer electron beam exposure apparatus including a load lock chamber according to one embodiment of the present invention.

FIG. 2 is a diagram showing details of a load lock chamber of FIG. 1 in a state where a wafer is carried in and out;

FIG. 3 is a diagram showing a state where the load lock chamber is evacuated or leaking.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Vacuum apparatus main body 2 Gate valve 3 Load lock chamber 4 Gate valve 5 Atmosphere chamber 7 Sample (wafer) 11 Charge beam exposure apparatus 13 Sample chamber 15 Stage 17 Vacuum exhaust port 19 Valve 21 Vacuum pump 31 Load lock chamber main body 32 Loading / unloading port 33 Room 33a Outside cover 33b Inside cover 35 Top / side cover 35a Top plate 35b Side plate 36 Gap 37 Sample table 39 Leak port 41 Lower cover 42 Sample table vertical movement mechanism 43 Leak line 45 Leak valve 47 Vacuum exhaust port 48 Valve 49 Vacuum Pump 51 Atmospheric chamber main body 53 Sample carrier 61 Arm

Claims (4)

[Claims] 1. A load lock chamber which is placed between a vacuum device for processing a sample under a vacuum and the outside of the atmosphere, and carries a sample into and out of the vacuum device; A load lock chamber provided with a dustproof cover for covering. 2. The load lock chamber according to claim 1, wherein said dustproof cover is provided so as to cover an upper surface and side surfaces of said sample. 3. The load lock chamber according to claim 2, wherein said dustproof cover is further provided so as to cover the sample or a base under which the sample is mounted. 4. The load lock chamber according to claim 1, wherein a vacuum exhaust port is provided outside the space covered by the cover, and a leak port is provided in the space.