JPS62247531A - Method for washing - Google Patents

Abstract

PURPOSE:To wash with facility and high efficiency a semiconductor wafer after scribing for which immersion washing may be accomplished only under certain restrictions and thereby to bring about improvement in the productivity and reliability in semiconductor devices by a method wherein a holder mounted with a semiconductor wafer is positioned under a cover and a washing liquid is allowed to flow toward the periphery between the cover and the wafer and the holder. CONSTITUTION:A holder 2 mounted with a wafer 1 provided with an adhesive tape 2a on its rear side and scribed as far as the rear side is placed under a Bernoulli's shade 4. Washing water is allowed to flow between the Bernoulli's shade 4 and the wafer 1 and holder 2 along stream lines 6 toward the periphery. The Bernoulli's shade 4 is gradually lower toward the periphery, which narrows the gap between the shade 4 and the wafer 1 and holder 2. This increases the speed of the washing water and, in line with Bernoulli's theorem, there is a decrease in pressure just above the wafer 1 and holder 2. The negative pressure sucks up power or tiny pieces of foreign substances and wash them away. Simultaneously, the wafer 1 and holder 2 themselves are sucked up.

Description

[Detailed Description of the Invention] [Summary] The present invention relates to a method for cleaning semiconductor wafers, etc., in which a cleaning liquid is flowed in a peripheral direction between a holder on which a wafer is mounted and a cover, and the cleaning liquid exerts a Bernoulli effect on the wafer and the holder. By using this effect to clean the deposits, it is possible to obtain a good cleaning effect on semiconductor wafers, etc. after scribing, and it can also be used for automatic transportation.
The aim is to improve the productivity and reliability of semiconductor devices, etc.

[Industrial application field]

The present invention relates to a cleaning method, and particularly to an improvement in a cleaning method for removing powder, debris, etc. attached to the surface of a semiconductor device during the manufacturing process thereof.

In the manufacturing process of semiconductor devices, etc., preventing and removing contamination from wafers, etc. is a key to stability, reliability, etc., and the cleaning method used in each process must be determined based on the form of contamination, contaminants, etc. First, the condition of the object to be cleaned,
It is necessary to be well adapted to the transport method of the production line and to obtain sufficient effects.

[Conventional technology]

As is well known, in order to manufacture semiconductor devices, a large number of required integrated circuits, etc. are simultaneously formed on a semiconductor wafer as large as possible, and this wafer is scribed at predetermined positions.
cribbing) into individual chips.

Traditionally, the amount of scribing is wide (the scribing method used is to make a grid-like cut on the wafer using a diamond cutter, diamond blade, etc., leaving about 150 to 200 mm on the back side, and then support this with a holder). After cleaning in a cleaning tank, the pieces are divided by rubber rollers at the cut locations, but in this conventional method,
There are problems such as pressure being applied to the integrated circuits etc. during the final division, and the cleaning process being a batch process which is not suitable for in-line automatic transport.

For the purpose of dealing with this point, as shown in the schematic side view in FIG. A method of cleaning by pouring with a jet nozzle 14 or the like is being introduced.

However, this method has difficulty in uniformly cleaning the entire surface of the wafer, and as shown in the schematic plan view of FIG.
They tend to be scattered all over the surface. There is a great risk that the Si powder etc. that remain scattered in this way will damage the integrated circuits etc. on the surface of the chip when each chip/knob is sucked with a vacuum chuck after cleaning.

[Problem that the invention seeks to solve]

In order to improve the productivity and reliability of semiconductor devices, etc., we have developed a cleaning method that solves the above-mentioned lack of cleaning effect by pouring water from above the wafer using a jet nozzle, etc., and is suitable for in-line automatic transportation. A cleaning method is strongly desired.

[Means for solving problems]

The problem is that a holder carrying a wafer is placed under a cover, and a liquid flows circumferentially between the cover, the wafer, and the holder, and the liquid exerts a Bernoulli effect on the wafer and the holder. The problem is solved by the cleaning method according to the present invention, which uses the cleaning method to clean the acid wafer and deposits on the holder.

[For production]

According to Bernoulli's theorem, in a steady flow of a fluid that has no viscosity and does not shrink, p+'Apv Z +r z -constant holds for one streamline. However, p is the pressure, ρ is the density of the fluid, ■ is the flow velocity, γ is the weight of the unit volume of the fluid, and 2 is the height from the reference horizontal plane. Note that this relationship holds true regardless of the location when there is no vortex, and also holds true in the case of contracting fluid, unsteady motion, etc., which is a generalization of the above formula.

This theorem shows that as the flow velocity V increases, the pressure p decreases and can even take a negative value, and the effect exerted by this pressure is called the Bernoulli effect.

The present invention applies this effect by placing a holder carrying a wafer under a cover, and flowing a liquid such as water in a peripheral direction between the cover, the wafer, and the holder.
The deposits on the wafer and holder are cleaned using negative pressure exerted by the liquid on the wafer and holder.

By utilizing the Bernoulli effect in this manner, adhering powder, debris, etc. are washed out, and a good cleaning effect can be obtained.

Furthermore, it is also possible to transport the wafer and holder during cleaning in order to pull them up under negative pressure, which also has the effect of shortening the time between processes.

〔Example〕

The present invention will be specifically explained below using examples.

FIG. 1 shows an embodiment of the present invention, and FIG. 1A is a schematic plan view thereof, and FIG.

In the figure, 1 is a wafer, 2 is a holder, and 2a is a bottom part of the holder 2 using tape, for example, and the wafer 1 is
is glued on the back side, 2b is the frame part, 4
5 is a washing water outlet provided on the lower surface of the Bernoulli umbrella, 6 is an example of a streamline of washing water, 7 is a water conduit, and 8 is a second cover.

In this embodiment, as in the conventional example, tape 2 is placed on the back surface in advance.
When cleaning the wafer 1 on which the wafer a has been bonded and scribed to the back side, the holder 2 with the wafer l mounted thereon is placed under the Bernoulli umbrella 4, and a streamline is created between the Bernoulli umbrella 4, the wafer 1, and the holder 2. As schematically shown at 6, the cleaning water is flowed in the peripheral direction.

The Bernoulli umbrella 4 gradually becomes lower from the center to the periphery, and the gap below it narrows, and the flow rate of the cleaning water is high near the top surfaces of the wafer 1 and holder 2, and the pressure decreases as described above due to Bernoulli's theorem, creating a negative pressure. The powder, particles, etc. that are generated and adhered are pulled up and washed away. At the same time, the wafer 1 and holder 2 themselves are also pulled up.

In the wafer cleaned according to this example, compared to the cleaning result according to the conventional example explained with reference to FIG. Remarkable effects have been achieved in improving yield and reliability.

Although the above-mentioned embodiment cleans wafers after scribing, it is clear that similar effects can be obtained on wafers and the like that have been subjected to previous processes.

〔Effect of the invention〕

As explained above, according to the present invention, it is possible to easily obtain a good cleaning effect on, for example, semiconductor wafers after scribing, for which immersion cleaning is restricted, and it is also possible to carry out automatic conveyance using an in-line method. Great effects can be obtained in improving the productivity of equipment, reliability, etc.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of an embodiment of the present invention, FIG. 2 is a schematic diagram of a conventional example. In the figure, 1 is a wafer, 2 is a holder, 2a The bottom part of the holder 2 to which the wafer 1 is attached, 2b is the frame part of holder 2, 4 is a cover (Bernoulli umbrella), 5 is a cleaning water outlet; 6 is an example of streamlines of washing water, 7 is a water pipe, 8 indicates the second cover. Implementation fy-Hakkan 4 diagram n γ resistance

Claims (1)

[Claims] A holder carrying a wafer is positioned under a shroud, and a liquid is caused to flow in a circumferential direction between the shroud, the wafer, and the holder, and the Bernoulli effect of the liquid on the wafer and the holder is utilized to generate the liquid. A cleaning method characterized by cleaning deposits on a wafer and the holder.