JPH04204035A - Sample pretreatment device - Google Patents

Abstract

PURPOSE:To enable a sample to be decomposed and condensed without being affected by contamination from environment by using a structure which allows decomposition of the sample and condensation of the decomposed sample to be operated continuously using a same container. CONSTITUTION:A specified amount of decomposition liquid 3 is fed to a container 2, a sample wafer 4 is placed on it, a closing lid is placed from an upper part, and then a screw is clamped. When a decomposition device is placed on a heater 1 and then is heated, a decomposition liquid is evaporated, a thin film on a surface of a wafer is dissolved, and then is cooled and dropped. It is repeated while heating for a certain time by a heater and a thin film including a contamination substance on the surface of the wafer is dissolved entirely. When the sample after decomposition operation is condensed by the column condensation method, the container 2 with the decomposition liquid 3 is removed and is connected to a container for condensing column 7. By pressing a pure high-pressure gas from a gas introduction port 8, the decomposition liquid 3 is introduced to a condensation column 10 through a discharge port 9 and a target constituent is condensed, thus enabling an extremely small amount of wafer contaminated object to be analyzed with a high sensitivity and high accuracy.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a sample pretreatment device for sample decomposition and concentration in the analysis of wafer contaminants.

[Prior Art] Conventionally, as a sample decomposition method used to analyze wafer surface contaminants, a wafer is immersed in a sealed container containing pure water, as in Japanese Patent Application Laid-Open No. 61-38547, and The method used was to dissolve the acid vapor generated in pure water to decompose the sample. However, according to this method, since the decomposed sample liquid must be handled in an open state after the sample has been decomposed, it is susceptible to contamination from the environment during pretreatment operations such as concentration.

[Problem to be solved by the invention] The above-mentioned conventional technology does not take into account contamination from the environment during pre-treatment operations such as concentration, which are performed after decomposition of wafer surface contaminants and before quantitative determination using an analyzer. This caused problems in accurately analyzing trace amounts of contaminants, which are a problem in the manufacture of semiconductor devices.

An object of the present invention is to provide a preprocessing device that can decompose and concentrate a sample without receiving contamination from the environment in order to analyze extremely small amounts of wafer contaminants with high sensitivity and precision. shall be.

[Means for solving the problem] In order to achieve the above objective, the structures of the sample decomposition device and the concentration device are unified, and the structure is such that the sample decomposition liquid can be combined with the decomposition container into the concentration device. be.

[Function] The container used for sample decomposition can be integrated as part of a concentrator that concentrates the decomposition solution, and the process from decomposition of the sample to concentration of the decomposition solution can be performed continuously, so sample pretreatment can be carried out from the environment. can be carried out without contamination.

[Example] An example of the present invention will be described below with reference to FIGS. 1 and 2.

FIG. 1 shows an embodiment of the sample decomposition device, in which (a) is a full-surface decomposition device for dissolving the entire surface of a wafer, and (b) is a local decomposition device for dissolving a local part of the wafer.

FIG. 2 shows an embodiment of the sample liquid concentrator, in which (c) is a column concentrator, (b) is a reaction vessel, and (c) is a precipitation filtration device.

The sample decomposition operation in this example is performed using the full-surface decomposition apparatus shown in FIG. 1(a) when analyzing contaminants on the entire surface of the wafer, and by using the full-surface decomposition apparatus shown in FIG. 1(a) when analyzing local contaminants on the wafer. b)
This is done using a local decomposition device. In the full-scale decomposition apparatus shown in (a), a predetermined amount of decomposition liquid 3 is poured into a sample container 2, a sample wafer 4 is placed thereon, a sealing lid 5 is placed on top, and the screw is tightened.

When the decomposition device is placed on a heater 1 and heated, the decomposition liquid evaporates, dissolves the thin film on the wafer surface, and then cools and falls. This process is repeated while the wafer is heated for a certain period of time, and the thin film containing contaminants on the wafer surface is completely dissolved. If necessary, a cooling plate 6 can be attached to the airtight lid to cool the wafer from the back side and promote condensation of the decomposition liquid on the wafer surface.

In the local decomposition device shown in (b), removable small cells 2' are screwed into the sample container 2, and a predetermined amount of decomposition liquid 3 is poured into each small cell 2', and the wafer 4 is placed in the same way as in (a). After placing the lid on and closing the airtight lid 5, turn on the heater l for a certain period of time.
Heat it up. In this case, only the portion of the thin film on the wafer surface that is in contact with the small cells 2' is dissolved in each decomposition solution.

Next, the concentration operation of this example will be explained using FIG. 2. When concentrating the sample solution after the decomposition operation using the column concentration method, use the column concentration device (c). That is, the decomposition container 2 or small cell 2 containing the decomposition 'e3 after the completion of the decomposition operation
° and connect it to column concentration container 7. By pressurizing clean high-pressure waste from the waste introduction port 8, the decomposed liquid 3
is led to the concentration column 10 through the discharge port 9, and the target component in the decomposition liquid is concentrated. When the sample solution after decomposition is concentrated by solvent extraction or precipitation filtration, a predetermined reaction is first carried out using the reaction vessel (d). That is, as in (c), the sample container 2 or small cell 2' containing the decomposition solution 3 is connected to the reaction container 12, and after adding the extraction solvent and the additive solution 11 for the precipitation reaction, the cap 13 is closed and shaken. etc. to allow the reaction to proceed. After the reaction is completed, for example, in the case of concentration by sedimentation filtration, filtration is performed using the sedimentation filtration apparatus shown in (e). That is, the cap 13 is removed and the filter filtration device 14 is connected to that part. Filter filtration device 1
4, the filter 15 is fixed on the filter plate 16 with a jig, and after fixing the tip of the filter filtration device to the suction bottle, the connection between the decomposition vessel 2 and the reaction vessel 12 is loosened and the suction bottle is attached. By suctioning from the sample liquid, the precipitate in the sample liquid is collected on the filter paper.

According to the present invention, it is possible to decompose a sample and concentrate the decomposition solution without exposing it to the outside air, so that contamination from the environment can be significantly reduced.

〔Effect of the invention〕

According to the present invention, it is possible to decompose a sample and concentrate the decomposition solution without contamination from the environment, making it possible to analyze extremely small amounts of wafer contaminants with high sensitivity and precision. effective in doing so.

[Brief explanation of the drawing]

FIG. 1(a) is a cross-sectional view of a full-surface disassembly apparatus for melting the entire surface of a wafer according to an embodiment of the present invention, and FIG. 1(b) is a cross-sectional view of a local disassembly apparatus for melting a local part of a wafer. . FIG. 2(c) is a diagram showing a column concentration device according to an embodiment of the present invention, FIG. 2(d) is a diagram showing a reaction device, and FIG.
) is a diagram showing a sedimentation filtration device. ■... Heater, 2... Sample container, 2'... Local decomposition cell, 3... Decomposition liquid, 4... Wafer, 5...
Airtight lid, 6...Cooling plate, 7...Column concentration container, 8...Gas inlet, 9...Discharge port, 10...Concentration column, 11...Additive liquid, 12... ...Reaction container, 1
3... Cap, 14... Filter filtration device, 1
5... Filter, 16... Filter plate, 17... Filter tightening jig.謬 1 口（し） （C） 2nd <e>

Claims (1)

[Claims] 1. A sample pretreatment device, characterized in that it has a structure that allows the decomposition of a sample and the concentration of a decomposed sample solution to be performed continuously using the same container.