JPH07169808A - Detector for wafer with metallic film - Google Patents

Abstract

PURPOSE:To prevent the dipping treatment of a wafer with a metallic film such as an aluminum film by a dip type wetting device, and to obviate contamination due to a metal in a treating liquid. CONSTITUTION:A wafer 1 before treatment by a dip type wetting device is irradiated with infrared ray 4, a silicon wafer 1 is irradiated with infrared ray 4 and the presence or absence of a wafer with a metallic film are detected by utilizing the difference of infrared transmittance between the silicon wafer and the metallic film such as an aluminum film in a detector.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a detection device for a wafer with a metal film used during a semiconductor manufacturing process.

[0002]

2. Description of the Related Art Conventionally, in the process of manufacturing a semiconductor device,
When cleaning or etching a wafer using a dip type wet machine, the presence or absence of a metal film that may contaminate the wet machine such as an aluminum film or a silicide film formed on the wafer surface should be checked by the Before setting, it was checked visually by the operator.

[0003]

In the conventional visual inspection,
Due to work mistakes such as oversight, the wafer with metal film is processed by the wet machine, the metal film is dissolved in the chemical solution of the wet machine, and then the metal ions are diffused and contaminated in the wafer processed by the machine. Therefore, there is a problem in that the yield is significantly reduced. Further, in order to prevent the above problems, it is necessary to have a highly skilled worker as a checker to perform the work, and there is a problem that the work man-hour is also heavy.

[0004]

In order to detect whether or not a wafer with a metal film is present, the infrared ray of the present invention has a high transmittance to a silicon wafer or the like, in order to detect whether the wafer has a metal film or not. The characteristic is that it attenuates against a metal film such as an aluminum film. This device includes an infrared light emitting unit, a wafer holder, an infrared light emitting unit, and a sensor amplifier unit.

[0005]

The present invention will be described below with reference to the drawings. FIG. 1 is a block diagram of a detection apparatus for a wafer with a metal film according to an embodiment of the present invention.

The wafers 1 arbitrarily taken out one by one from the product carrier 7 are set on a wafer holder 2 made of an infrared transmitting material, and infrared rays 4 are irradiated onto the wafer 1 from an infrared emitting section 3. At this time, in order to detect the patterned wafer with the metal film, the wafer holder 2 on which the wafer 1 is set is slowly moved in the vertical and horizontal directions or the rotation direction by the linear movement mechanism or the rotation mechanism to increase the measurement area. The irradiated infrared rays 4 hardly pass through the wafer 1 in the portion where the metal film such as aluminum exists, pass through the wafer 1 only when there is no metal film such as aluminum, and are taken into the infrared light receiving portion 5. The infrared rays taken in are sent to the sensor amplifier unit 6 and electrically analyzed.

The electric output of the sensor amplifier section 6 is shown in the graph of FIG. The horizontal axis of the graph is a time axis and represents the movement of the wafer 1 set on the wafer holder 2. The vertical axis represents the intensity of received infrared rays. FIG. 2 (a) shows a case of a normal wafer having no metal film such as aluminum deposited thereon, and FIG. 2 (b) shows a case of an aluminum film deposited to a thickness of about 1 μm on the entire wafer surface. 2 (c)
Is the infrared intensity when aluminum of the wafer of FIG. 2B is patterned. The results shown in FIGS. 2B and 2C are clearly different from the results shown in FIG. 2A. By setting the abnormality detection threshold of the sensor amplifier unit 6, a wafer with a metal film such as aluminum is formed. Can be detected.

In the above-described embodiment, the case where one wafer is arbitrarily extracted from the product carrier and inspected is explained. As an application example thereof, a case where a plurality of wafers are arranged in parallel on a wafer holder and are collectively inspected will be described.

As for the wafers to be inspected at this time, since all the wafers in the product carrier are transferred to the wafer holder for storage and are inspected at the same time, the presence or absence of, for example, several wafers with a metal film mixed in the product carrier. Can be detected. In this way, since it is possible to inspect whether or not defective wafers are mixed for each product carrier lot, only one wafer can be inspected only for product carriers that have defective wafers.
Since it is only necessary to inspect each sheet, the inspection time can be shortened.

[0010]

As described above, according to the present invention, the presence or absence of a metal film such as an aluminum film is automatically detected by inspecting the deposition of the metal film on the wafer before being processed by the dip type wet machine using infrared rays. It is possible to detect it. As a result, it is possible to reliably prevent metal contamination of the dip-type wet apparatus and prevent a large reduction in yield of semiconductor integrated circuits.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an embodiment of the present invention.

FIG. 2 is a diagram showing the intensity of transmitted infrared rays in one embodiment. FIG. 2 (a) shows the case where a metal film is not deposited, and FIG. 2 (b) shows the case where an aluminum film is deposited on the entire surface. FIG. 3C is a graph showing the case where the aluminum film is patterned.

[Explanation of symbols]

 1 wafer 2 wafer holder 3 infrared light emitting part 4 infrared light 5 infrared light receiving part 6 sensor amplifier part 7 product carrier

Claims (1)

[Claims] 1. An infrared light emitting section for irradiating infrared rays on a surface of a wafer to be inspected, which is set up on a wafer holder, an infrared light receiving section for receiving infrared rays transmitted through the wafer, and the presence or absence of a metal film adhered to the wafer. A detector for a wafer with a metal film, comprising: a sensor amplifier for detecting the intensity of the transmitted infrared light.