JPH0638242U - Wafer operation box for natural oxide film prevention - Google Patents

Abstract

(57) [Abstract] [Purpose] When performing inspection of a wafer during the semiconductor manufacturing process, a natural oxide film is formed on the surface of the wafer to prevent the formation of a natural oxide film due to oxygen in the air. A wafer operation box for oxide film prevention is provided. [Structure] An operation room 2 formed in a box shape so as to be shielded from the outside air, and a glove 3 for performing an operation by putting a hand inside the operation room, and remove oxygen in the operation room. A natural oxide film preventing wafer operation box 1 was constructed by providing an oxygen scavenger 7 for this purpose.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a wafer operation box which is used in a process such as an inspection or a test when a semiconductor device is manufactured using a silicon wafer and which prevents a natural oxide film from being generated on the silicon wafer.

[0002]

[Prior art]

 In semiconductor device manufacturing, when a wafer is left in the air for testing and inspection before and after thin film formation such as CVD, PVD, and sputtering, and gate electrode formation process, the surface of the metal thin film formed on the wafer surface It is known that oxygen is oxidized by oxygen in the air to form a natural oxide film (Natural Oxide).

The formation of this natural oxidation causes, for example, a decrease in conductivity and a decrease in interlayer strength to cause delamination, which is a serious defect in a semiconductor device as a product. A process of removing a natural oxide film was provided in the device to remove the naturally-occurring oxide film (peeling), and then various treatments were performed.

As a conventional method for removing the natural oxide film, there is known a method of removing the natural oxide film by immersing it in a cleaning solution containing an acid such as hydrofluoric acid as a base.

[0005]

[Problems to be solved by the device]

However, in the conventional method of removing the natural oxide film by washing with hydrofluoric acid, for example, there is a fear that a film other than the natural oxide film (for example, a SiO ₂ film) may be removed if it is immersed too much. It was In addition, a dedicated device is required to perform the cleaning for removing the natural oxide film in each process, and the cleaning device dedicated to the natural oxide film removal is expensive, which increases the cost of the manufacturing device and further processes. There was a problem that productivity increased by adding one process.

The present invention is intended to solve the above-mentioned drawbacks of the prior art, and prevents generation of a natural oxide film on the surface of a metal thin film or the like formed on the surface of a wafer in a wafer processing process in the manufacture of semiconductor devices. It is an object of the present invention to provide a wafer operation box for preventing natural oxide film.

[0007]

[Means for Solving the Problems]

 The wafer operation box for natural oxide film prevention of the present invention is a wafer operation box used for operations such as wafer testing and inspection during the process of processing semiconductors by processing silicon wafers. As described above, it has a box-shaped operation room and a glove for putting an hand inside the operation room to perform an operation, and an oxygen scavenger for removing oxygen in the operation room. It is characterized by

[0008]

【Example】

 Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 shows an embodiment of the present invention, FIG. 1 is a front view showing an example of a native oxide film preventing wafer operation box of the present invention, and FIG. 2 is a side view of the wafer operation box shown in FIG. It is a partially cutaway side view.

As shown in FIGS. 1 and 2, a wafer operation box 1 for preventing a natural oxide film (hereinafter, simply referred to as an operation box) 1 of the present invention is a box-shaped operation chamber that is shielded from outside air. 2 and a glove for putting an operator's hand in the operation chamber to perform an operation, and an oxygen removing agent 7 for removing oxygen in the operation chamber 2 is provided.

Further, as shown in FIG. 2, the operation box 1 of the present embodiment is provided with a UL PA filter 8 in the upper part of the operation room 2, and the inside of the operation room is evacuated through the oxygen scavenger provided on the back side of the operation room. Alternatively, a blower 10 is provided below the operation chamber 2 so that the nitrogen gas circulates (in the direction indicated by the arrow in the figure).

Further, the operation box 1 is provided with exhaust gates 13 and 14 for discharging the air inside the operation chamber 2 to the outside, and an oxygen free gas inside the operation chamber 2 is provided in the lower part of the operation box. Nitrogen inlets 11 and 12 for introducing the nitrogen are provided.

As shown in FIG. 1, a door 4 for loading and unloading wafers to and from the operation chamber 2 is provided on the front side of the operation box 1 so as to be openable and closable, and the door 4 is transparent glass so that the inside can be seen. 17 is fitted. An oxygen concentration meter 15 for displaying the oxygen concentration in the operation chamber 2 and a differential pressure gauge 16 for displaying the pressure in the operation chamber 2 are provided on the upper front side of the operation box 1.

It is important to provide the oxygen scavenger 7 in the operation box of the present invention. By storing the oxygen scavenger 7 while shielding the operation chamber 2 from the outside air, oxygen in the operation chamber can be removed and a natural oxide film can be effectively prevented from being formed on the wafer surface. Oxygen cannot be completely removed only by replacing the inside of the operating chamber with oxygen-free nitrogen gas and sealing it, or by circulating oxygen-free nitrogen gas in the operating box. It is necessary to remove the oxygen inside the operation box with an oxygen scavenger.

As the oxygen scavenger 7 used in the device of the present invention, various oxygen scavengers such as those that selectively adsorb oxygen and those that react with oxygen can be used. For example, metal powder such as iron powder, organic matter such as catechol and the like can be mentioned. Further, it is preferable that the oxygen scavenger 7 is formed in a cartridge type so as to be removable from the outside of the operation box 1 because it can be easily replaced when the oxygen scavenging ability is deteriorated. For example, by combining it with an indicator or sensor that shows the capacity of the oxygen scavenger 7 from the outside, when the indicator indicates the replacement time, the cartridge can be replaced with a simple operation, and the replacement work can be performed smoothly. it can.

Further, in addition to providing an oxygen scavenger in the device of the present invention, it is preferable to introduce oxygen-free nitrogen gas to pressurize the atmosphere at about 1 to 2 mm / Hg. Good The above-mentioned pressurization of about 1 to 2 mm / Hg is a pressure at which the internal nitrogen is circulated by a blower. By slightly pressurizing the inside of the operation chamber, oxygen in the air can be completely removed more efficiently.

The ULPA filter 8 provided under the oxygen scavenger 7 is for removing fine particles in the operation chamber, and it is possible to appropriately use HEPA, a medium performance filter or the like according to the level of wafer processing. it can.

The operation box 1 of the present invention can be used for inspections and tests during the semiconductor manufacturing process, and the surface of the wafer is a Si surface or a metal thin film forming surface, a pattern forming surface such as a gate electrode. As the metal thin film (including the pattern), there are Al, Au, Cu, Cr, Sn, W, Mo, and a reaction product (mixture) of these and Si on the surface. If the thin film is left in the air for a long time, it may be stored in the operation box.

Although not particularly shown, the operation box of the present invention preferably contains a water removing agent such as a dehydrating agent or a desiccant and is used together with the oxygen removing agent. The generation of a natural oxide film is greatly affected by moisture, and by controlling the moisture level in the operating room to a level below the level at which a moisture remover is used together, the generation of a natural oxide film can be prevented more effectively.

In the operation box of the embodiment shown in FIG. 1, the oxygen scavenger 7 is provided on the back side, the ULPA filter 8 is provided on the upper part of the operation room, and the blower 10 is arranged on the lower part of the operation room to form the operation box. Although formed, it is not particularly limited to this arrangement. As a general space factor, it is desirable to arrange each part of the filter, oxygen absorbent, blower, etc. in the height direction (vertical direction of the operation room), but depending on the arrangement of each processing equipment of the semiconductor manufacturing equipment. The arrangement of each part may be appropriately selected.

[0020]

[Action]

 Next, the operation of the device of the present invention will be described with reference to the embodiment shown in FIG. A silicon wafer having a metal thin film formed on the surface thereof by a CVD apparatus or the like is put into the operation chamber 2 and the inside is sealed. Next, oxygen-free nitrogen gas is introduced into the operation chamber 2 from the nitrogen inlet 11 or 12, and the internal air is exhausted from the air exhaust duct to be replaced. When the blower 10 is rotated to circulate the internal nitrogen gas through the oxygen scavenger 7 and the ULPA filter 8, the trace amount of oxygen contained in the nitrogen gas is removed by the oxygen scavenger, and the anoxic chamber 9 is anoxic. It is possible to prevent a natural oxide film from being generated on the wafer surface.

Before the wafer 4 is introduced into the operation chamber 2, the inside of the operation chamber may be replaced with oxygen-free nitrogen in advance. Although oxygen in the air can be removed by circulating the internal air without introducing nitrogen gas after the wafer is stored, the oxygen scavenger deteriorates if it is replaced with nitrogen gas in advance as described above. Can be prevented.

When the oxygen in the interior is removed by the oxygen scavenger, the oxygen partial pressure is reduced, so that oxygen-free nitrogen gas is introduced to keep the pressure in the operation room at atmospheric pressure at all times. This is preferable because it is possible to more reliably prevent oxygen from entering due to air flowing into the operation room from the outside. As described above, it is more preferable to apply a pressure of about 1 to 2 mm / Hg.

[0023]

[Effect of device]

 As described above, the wafer operation box for preventing the natural oxide film of the present invention adopts the structure provided with the oxygen scavenger, so that the wafer on which the metal thin film is formed is inspected during the semiconductor manufacturing process. By using the operation box of the present invention, it is possible to prevent the formation of a natural oxide film on the surface of the wafer when the wafer is left in the air. Thus, it is possible to prevent product defects due to the natural oxide film in the inspection process when manufacturing semiconductor devices. The device of the present invention has a simple structure and can be provided at low cost.

Therefore, it becomes unnecessary to remove the natural oxide film by using an expensive cleaning device for removing the natural oxide film between the processing devices as in the conventional case, and the cost of the manufacturing equipment is reduced. be able to. In addition, the step of removing the natural oxide film is not required, and the productivity is improved, which is a great practical effect.

Further, in order to remove internal oxygen, it is conceivable that the inside of the operation box is decompressed to remove oxygen and become a high vacuum state. However, under a high vacuum, mechanical operation of the internal device is not possible. There is a problem of delay and it is necessary to reduce the pressure to near normal pressure with oxygen-free nitrogen gas, so it is very troublesome to perform depressurization and pressurization. However, since the device of the present invention removes oxygen by the oxygen scavenger, it is possible to bring it to atmospheric pressure or a slight pressurization state. There is an advantage that the operation can be performed at the same speed as when operating in normal air without delaying the movement, and there is no need to decompress the inside of the operation room or to return to normal pressure again.

[Brief description of drawings]

FIG. 1 is a front view showing an example of a native oxide film preventing wafer operation box according to the present invention.

2 is a partially cutaway side view of the natural oxide film preventing wafer operation box in FIG.

[Explanation of symbols]

 1: Wafer operation box for natural oxide film prevention 2: Operation room 3: Globe 7: Oxygen scavenger

Claims (1)

[Scope of utility model registration request] 1. A wafer operation box used for operations such as wafer testing and inspection in the process of manufacturing a semiconductor by processing a silicon wafer, the box being formed in a box shape so as to be shielded from the outside air. Natural oxide film prevention, characterized in that it has an operation room and a glove for putting a hand inside the operation room to perform an operation, and is provided with an oxygen scavenger for removing oxygen in the operation room. Wafer operation box.