JPS619655A - Method and mechanism for fixing body - Google Patents

Abstract

PURPOSE:To increase an amt. of X-rays contributing to exposure and to shorten exposure time length by using residual electrostatic force for position fixing. CONSTITUTION:This position fixing device 40 can be set in a housing chamber 43 by substituting the inside of an airlock chamber 41 with the outer atmospheric air and opening a gate door 42. Then, the device 40 can be transferred to just below an X-ray source 11 in the vacuum chamber B 48 by closing the door 42, substituting the airlock chamber 41 by the vacuum atmosphere, and actuating a transfer mechanism 46 and a feeding rod 47. on the other hand, the device 10 can be taken out by reversing said action after transferring the X-ray pattern.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention is mainly applicable to X-ray pattern transfer, dry etching, or the like in the semiconductor device manufacturing process.

A method of positioning and fixing a semiconductor substrate (hereinafter referred to as a wafer) and an original pattern (hereinafter referred to as a mask) for processing equipment that uses a vacuum or reduced pressure atmosphere such as dry coating, and a mechanism for positioning and fixing. It is something.

[Conventional technology]

Conventionally, as a mask and wafer positioning and fixing device used in this type of device, an example of an X-ray pattern transfer device was used as the first example.
This will be explained using the diagram and FIG.

Positioning between the mask 1 and the wafer 2 is performed by a mask fine movement mechanism 4 that observes equipment alignment marks made up of preforms on the mask 1 and wafer 2 with an optical sensor 6, and adjusts the attitude and position of the mask 1 based on the results. Operate and align. The mask 1 is integrated with the mask holder 5, and can be attached to and detached from the mask fine movement mechanism 4 via the vacuum chuck A6, and the wafer 2 from the vacuum chuck B7. The seal ring 8 is made of rubber, and a part of its inner peripheral surface is brought into contact with the lower surface of the wafer 2, and a part of its outer peripheral surface is brought into contact with the mask holder 5, respectively, to keep the contact surfaces vacuum-tight. After aligning the wafers 2, if the hose port 9 is evacuated, the mask 1. Wafer 2. Mask holder 5 and seal ring 8
The closed space formed by the wafer 2 is evacuated, and as shown in FIG. 2, the mask 1 and the wafer 2 are brought into close contact with each other due to atmospheric pressure, and the two are positioned and fixed.

FIG. 6 shows a method of X-ray exposure using this positioning and fixing device 1o, in which the X-ray light source 11 is in a vacuum chamber, 412
It is separated from the helium atmosphere chamber 15 by a metal beryllium film 15 that transmits X-rays 14 well. 16.1
7 is a helium atmosphere 13 to prevent the attenuation of the X-rays 14 due to the intrusion of Daimaru at the gas helium supply and exhaust ports.
This is to keep the internal pressure slightly higher than atmospheric pressure at all times.

18 is the X-ray shutter, 19 is the positioning and fixing device 1o
This is a manual handle for attaching and detaching the device to the line exposure position.

Therefore, by opening and closing the X-ray shutter 18.

X-ray 1 is applied to the pattern shape of mask 1 onto the photosensitive material on wafer 2.
4 to print and transfer.

[Problem that the invention seeks to solve]

As described above, the positioning and fixing device 10 utilizes the pressure difference between atmospheric pressure and vacuum, and it is almost impossible to use it in a vacuum or a reduced pressure atmosphere A close to a vacuum. Close contact between the mask 1 and the wafer 2 surface is unavoidable, and pattern destruction is likely to occur due to adhesion and peeling of the photosensitive agent on the wafer 2 surface and the mask 1.
Due to the habit of the ring or the frictional force of the vacuum-tight contact surface, the alignment may go awry in a certain direction when vacuuming, so it is necessary to adjust the alignment with a correction amount in advance, or the mask 1 There are various drawbacks such as difficulty in highly accurate positioning between the wafer 2 and the wafer 2.

[Failure to solve the problem]

In order to solve these drawbacks, the present invention uses two residual electrostatic forces to power the positioning and fixing between the mask 1 and the wafer 2, a positioning and fixing structure, and a plate spring with high rigidity in the in-plane direction.

It is characterized by utilizing the characteristic of low rigidity in the thickness direction.

As a result, it is possible to transfer the positioning and fixing device to a vacuum or a reduced pressure atmosphere close to vacuum, or to facilitate attachment and detachment by positioning and fixing the mask 1 and the wafer 2 without contact, to maintain the mask, or to improve the accuracy of exposure pattern formation. and so on.

〔Example〕

FIG. 4 is a sectional view of two embodiments of the present invention, showing the state before the mask 1 and wafer 2 are positioned and fixed. 2° is a mask holder made of a conductive material that holds the mask 1.

Reference numeral 21 designates an electrostatic pad A that electrostatically attracts the mask holder 20, and is integrated with an elevating frame 22 made of a conductive material. Reference numeral 26 denotes a leaf spring A, both ends of which are connected to the lifting frame 22 and the transfer auxiliary plate 24, respectively. Reference numeral 25 denotes electrostatic /<rad B which is electrostatically attracted to both sides of the lifting frame 220. Reference numeral 26 denotes a leaf spring B, whose both ends are connected to the electrostatic pad B 25 and the transfer auxiliary plate 24, respectively. 2
7 is a vacuum chuck C for attaching and detaching the transfer auxiliary plate 24 to and from the alignment device main body 28. 29 is an electrostatic wafer chuck.

FIG. 5 shows a state in which the electrostatic pad A21 and the electrostatic pad B25 are operated, and the relative position between the mask 1 and the Ueno 2 is positioned and fixed by residual electrostatic force.

FIG. 6 shows the electrostatic pad (21 and electrostatic pad B25).
FIG. 2 is an explanatory diagram of the basic structure of , and an adsorption/fixing method using residual electrostatic force. 3G is a conductor and 51 is an insulator.

62 is an electrode made of a conductor formed on an insulator, 53 is a dielectric film, 54 is a power supply unit that applies a potential to the electrode 62, 35 is a DC power supply, 66 is an AC power supply, and 67 is a grounding unit. 68
59 is a switching section for selecting the potential to be supplied to the electrode 32, and 59 is a connection terminal.

7 shows a state of electrostatic attraction due to accumulated charges of the conductor 30 and the electrode 62, and FIG. 8 shows a state of electrostatic attraction due to polarized charges of the insulating dielectric film 28.

In FIG. 6, the conductor 30 is at ground potential.

When a DC potential is applied to the electrode 32, according to Coulomb's law, an electrostatic force acts that is inversely proportional to the square of the distance, directly proportional to the square of the potential difference, and directly proportional to the relative dielectric constant between the conductor 60 and the electrode 63, resulting in conductivity. The body 30 and the electrode 62 are an insulating dielectric film 66
Fix it by suction through it.

Furthermore, as shown in FIG. 7, even if the DC power source 65 is disconnected after being fixed by suction, positive and negative charges remain between the conductor 30 and the electrode 3.
2, the adsorption fixation is maintained by this accumulated charge. Further, if the conductor 30 and the electrode 62 are grounded, the accumulated charge disappears and the suction/fixation part is released. However, if a certain potential difference or more is applied to the thickness of the dielectric film 35, as shown in FIG.
A polarized charge is generated that does not disappear even if the electrode 32 is grounded.

The suction surface orientation is maintained. In other words, a polarized negative charge does not create an attractive force because it has the same potential as the ground potential or charge, but a polarized positive charge gives a potential difference between it and the ground potential or charge.
Maintain suction fixation. To release this, connect to the AC power supply 36 shown in FIG.

Once an AC potential equal to the polarized charge is applied and the potential difference is gradually attenuated, the bipolarized charge disappears.

The suction fixation is released.

Because of this structure, in Fig. 4, after positioning the mask 1 and the square 2 in the same manner as before, the two mechanisms are set to ground potential and the electrostatic pad 421 and the electrostatic pad are connected. If a DC potential is sequentially applied to B25, the fifth
An electrostatic pad supported by a leaf spring A25 as shown in the figure,
421 is vertically, and the electrostatic pad B25 supported by the leaf spring B26 is horizontally, electrostatically attracted to the mask holder 20 and the lifting frame 22, respectively. In this case, leaf spring A2
5 and the leaf spring B26 have low rigidity in the plate thickness direction and high rigidity in the plate surface direction, that is, low rigidity in the electrostatic attraction direction and high rigidity in the positioning direction. Therefore, the positioning between the mask 1 and the wafer 2 is hardly affected, and the surface direction and gap direction between the mask 1 and the wafer 2 can be positioned and fixed with high rigidity. Even if the connection is cut, the positioning and fixation is maintained due to residual electrostatic force due to accumulated charges or polarized charges.

Therefore, if the suction of the vacuum chuck B6 and the vacuum chuck C27 is stopped and the mask fine movement mechanism 4 is driven and retracted,
While the positioning between the mask 1 and the sea urchin IS 2 is fixed, it can be easily separated from the alignment device 28 and can be transferred to a desired position. After the transfer, the mask 1 and the wafer 2 are released from the adsorption and fixation due to the residual electrostatic force by applying attenuation of the potential by connecting to the ground 67 or the AC power source 36.
can be attached and detached. However, the positioning and fixing of two pads indicates positioning and fixing in the surface direction and gap direction between the mask 1 and the wafer 2, that is, three-dimensional positioning, but the electrostatic pad (21h
Or, if either one of the electrostatic pads 825 is used, the two-dimensional positioning and fixing can be achieved even on the upper part of the neck. Further, the material of the dielectric film 63 is not limited, but an inorganic film with a high dielectric strength voltage such as silica wood oxide (SiO2), nitride silicone (SiN), or aluminum oxide (μ203) and a material with a low dielectric strength voltage may be used. It goes without saying that a polymer film that is easily polarized, such as polyethylene, polyimide, or 47-ethylene chloride, can be used, and a multilayer structure that is a combination of these materials may also be used. In addition, the mask holder 5, the material 6 of the conductor 60 and the electrode 62, as long as they are electrically conductive, and it goes without saying that both good conductors and semiconductors can be applied.
This is a configuration diagram for transferring an X-ray pattern to a vacuum atmosphere, and 40 is a main positioning and fixing device.

41 is the aerospace room, 42 is the gate door, 46 is the storage box,
44 is airtight bellows, 45 is gate pulp.

46 is a transfer mechanism, 47 is a feed rod, and 48 is a vacuum chamber B. Therefore, the aerodynamic chamber 41 is replaced with an atmospheric atmosphere,
By opening the gate door 42, the positioning and fixing device 40 can be set in the storage box 46. Next, close the gate door 42,
If the airlock chamber 41 is replaced with a vacuum atmosphere and the gate pulp 45 is opened, the transfer mechanism 46 and the feed rod 47
This positioning and fixing device 40 can be transferred under the X-ray light source 11 in the vacuum chamber B4B. Furthermore, by performing two or more operations in reverse after the X-ray pattern is transferred, the two positioning and fixing devices 40 can be taken out into the atmosphere.

〔Effect of the invention〕

As explained above, according to the second invention, residual electrostatic force is used as power for positioning and fixing.

Since it can be transferred not only in the atmosphere but also in a vacuum or reduced pressure atmosphere, X-ray exposure can be performed by positioning in the atmosphere and transferring in a vacuum. As a result, since a vacuum sealing film and gaseous helium are not required, the exposure time can be shortened by increasing the amount of X-rays contributing to exposure.

In addition, positioning and fixing using residual electrostatic force does not require power supply for adsorption and fixation during transfer, and attachment and detachment requires only the application of a potential and requires less energy, making transfer extremely easy.

In addition, the plate spring has high rigidity in the plane direction.

The three-dimensional positioning and fixing structure that utilizes the characteristic of low rigidity in the thickness direction enables non-contact positioning and fixation between the mask and the eight surfaces of the wafer, thereby preventing pattern destruction due to contact between the surfaces of both the mask 1 and the wafer 2. There is an advantage that positioning accuracy can be improved by positioning without friction or friction. In addition, the single positioning fixing is not limited to positioning and fixing between a mask and a wafer, but it is clear that it can be used as a transfer aid for objects that are difficult to transfer due to their shape, material, dimensions, etc.

Because the present invention has such characteristics, the present invention is not limited to X-ray pattern transfer devices, but also applies to original patterns for selectively etching or coating a sample, such as dry etching or dry coating in the semiconductor device manufacturing process, that is, a mask and a sample. If used for positioning and fixing or supplying a sample, the above-mentioned advantages can be effectively utilized.

[Brief explanation of drawings]

1 and 2 are sectional views of a conventional positioning and fixing device before and after operation, respectively, and FIG. 3 is a sectional view of an embodiment of the conventional positioning and fixing device. 4 and 5 are cross-sectional views of an embodiment of the device of the present invention before and after operation, respectively; FIG. 6 is an explanatory diagram of the electrostatic chuck fixing method in FIGS. 4 and 5;
8 and 8 are cross-sectional views of an electrostatic adsorption state due to residual charges and polarized charges, respectively, and FIG. 9 is a cross-sectional view of an embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Mask, 2... Wafer, 6... Optical sensor, 4... Mask fine movement mechanism, 5... Mask holder, 6
...Vacuum chuck A, 7...Vacuum chuck B, 8.
...Seal ring, 9...Hose port, 10...Positioning fixing device. 11... X-ray light source, 12... Vacuum chamber A, 13...
・Helium atmosphere chamber, 14...X-ray, 15...
Beryllium film. 16... Air supply port, 17... Exhaust port, 18... X-ray shutter, 19... Handle, 20... Mask holder,
21... Electrostatic pad A, 22... Lifting frame, 2
6...Plate spring A, 24...Transfer auxiliary plate, 25...
Electrostatic pad B, 26...Plate spring B, 27...Vacuum chuck C228...Device main body, 29...Electrostatic wafer chuck, 50...Conductor.

Claims (3)

[Claims] (1) Position the object to be transferred or the holder for the object to be transferred and the auxiliary transfer object, and then fix the object to be transferred or the holder for the object to be transferred and the auxiliary transfer object, and then become one body by the fixing. A method for transferring an object to be transferred or a holder for the transferred object and a transfer auxiliary body, and releasing the fixation of the holder for the transferred object or the transferred object and the transfer auxiliary body after the transfer, the holding of the transferred object or the transfer object. The tool and the transfer auxiliary body are electrically insulated and opposed to each other via a dielectric film, and the two are positioned. Then, a DC power source is connected to both opposing surfaces and a DC potential difference is applied to transfer the The object to be transferred or the holder for the object to be transferred and the transfer auxiliary body are fixed, and then the connection between the two opposing surfaces and the DC power source is disconnected, and the residual electrostatic force maintains the attraction of the two opposing surfaces to transfer the object. The holder for the object or the transferred object and the transfer aid are integrated, and the fixation can be released by grounding both opposing surfaces, or by connecting both opposing surfaces to an AC power source and gradually lowering the applied potential. A method for fixing an object, characterized in that the fixing method is carried out by releasing the adhesion caused by the residual electrostatic force between the opposing surfaces. (2) A transfer object or a holder and a transfer auxiliary body for the transfer object or the transfer object are provided, which are electrically insulated and opposed to each other via a dielectric film, and both opposing surfaces of the holder and the transfer auxiliary body for the transfer object or transfer object are provided. The plate spring is configured so that the plane direction is in the positioning direction, and the plate spring is arranged parallel to the two opposing surfaces so that the plate surface direction of the plate spring is in the positioning direction, and the plate thickness direction is in the electrostatic adsorption direction. One end of the leaf spring is connected to one of the opposing surfaces located on the side of the transfer auxiliary body, and the other end is connected to the transfer auxiliary body, and a DC voltage is applied to both of the opposing surfaces. A mechanism for fixing an object, comprising means for attracting and fixing the opposing surfaces by applying electrostatic force or residual electrostatic force. (3) A transfer object or a holder and a transfer auxiliary body are provided which are electrically insulated and face each other via a dielectric film, and both opposing surfaces of the holder and the transfer auxiliary body of the transfer object or transfer object are provided. The plate spring is configured so that the plane direction is in the positioning direction, and the plate spring is arranged parallel to the two opposing surfaces so that the plate surface direction of the plate spring is in the positioning direction, and the plate thickness direction is in the electrostatic adsorption direction. One end of the leaf spring is connected to one of the opposing surfaces located on the side of the transfer auxiliary body, and the other end is connected to the transfer auxiliary body, and a DC voltage is applied to both of the opposing surfaces. means for suctioning and fixing the two opposing surfaces by applying an electrostatic force or residual electrostatic force; a means for transferring the suction-fixed transfer object or a holder for the transfer object and a transfer auxiliary body as one; and the two opposing surfaces. 1. A fixing mechanism for an object, comprising means for grounding the object, or means for applying an alternating voltage between opposing surfaces to gradually reduce the alternating potential to release the suction fixation.