JPH02122536A - Wafer inspection device - Google Patents

Abstract

PURPOSE:To prevent a good chip on a wafer from being heated and badly influenced and effectively dry marked ink by selecting defective or nondefective chips on the wafer, marking the selected defective chips with ink, and irradiating a marked chip portion with spot light from a light source to dry the ink. CONSTITUTION:A signal is fed from a tester through a probe 31 of a probe card 30 to a pad 42 of a wafer chip 41, to inspect the electrical characteristics of the wafer chip. If a result of the inspection is a defective one, the signal is fed to an inker 51 to mark a defective chip with a defectiveness mark. Thereafter, a laser beam emanating from a laser oscillator device 83 is focused into a spot in out-focusing, the spot being slightly larger than the mark formed on the wafer chip 41 by the inker 51. Hereby, the ink forming the mark is irradiated, heated, and quickly dried.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a wafer inspection apparatus capable of reliably and quickly sorting out defective chips, and particularly to a wafer inspection apparatus equipped with marking means for marking defective chips.

[Conventional technology]

Generally, in a semiconductor device manufacturing process, a large number of semiconductor device elements (wafer chips) are formed on a single crystal wafer using a photo-etching technique. When the wafer chips are completed on the wafer, an electrical characteristic test of the wafer chips called a probe test is performed. This probe test is performed using an electrical property testing machine (tester) and a probe card. In other words, by touching the probe of the probe card to the electrode of the wafer chip,
The tester is used to inspect the electrical characteristics of wafer chips. Furthermore, a so-called wafer blower is used to fix the wafer with a chuck and bring the probes of the probe card into contact with all wafer chips on the wafer using an intermittent feeding mechanism. After completing this probe test, the wafer is cut and divided into individual semiconductor device wafer chips, and only those wafer chips that have passed the test are loaded into a container. In such a process, a non-defective chip that passed the inspection and a defective chip that failed the test are generally distinguished by the presence or absence of a defective mark made on the surface of the defective chip during a probe test. Conventionally, as shown in FIG. 2, the defect mark is placed on the wafer 1 after the probe 5 of the probe card is brought into contact with the electrode of the wafer chip 3 on the test wafer 1 and the electrical characteristics of the wafer chip 3 are tested by a tester. This was done by stamping ink on the surface of only defective chips using an ink cuff.

[Problems to be solved by the invention]

However, with this method, it is necessary to dry the stamped ink, which hinders the speed of wafer inspection work. Furthermore, the method of drying the ink has the disadvantage that the entire wafer with a large number of chips mounted thereon is usually placed in a high-temperature atmosphere, and the high temperature adversely affects not only defective chips but also good chips. An object of the present invention is to provide a wafer inspection apparatus that eliminates the drawbacks of the prior art.

[Means to solve the problem]

In other words, the features of this invention include an inspection means for selecting whether each chip on a wafer is good or defective, a marking means for marking the selected defective chips with ink, and a marked chip portion. The wafer inspection apparatus is characterized in that it has a drying means for drying the ink by irradiating light in a spot form from a light source. Another feature is that the light source of the ink drying means is a laser device or a halogen lamp. Another feature is that the laser light or halogen lamp light that is irradiated onto the chip portion in a spot-like manner is focused in a non-focused manner. By using this invention, a highly visible defect mark can be placed on any wafer chip without contaminating the surrounding area.

【Example】

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows the state of marking using the wafer inspection apparatus of the present invention. In the figure, a ring insert 10 is fixed to a head plate 20 of a test head (not shown), and a probe card 30 having a probe 31 is attached to an end face of the ring insert lo. The wafer 40 is held by the chuck 5o and moved up and down in the direction of the arrow, and the probe 31 of the probe card 30 is brought into contact with the pad (electrode) 42 of the wafer chip 41.
The electrical characteristics of the Then, the wafer inspection apparatus fixes the wafer 4o with the chuck 50, and moves the probes 3 of the probe card 30 over all the wafer chips on the wafer 40 using an intermittent feeding mechanism consisting of an
Touch 1. A marking means 51 for applying an ink mark is attached to the ring insert 10 via an attachment device. This marking means 51 can be a conventionally used in-force. The input force is applied to the needle 53 that discharges ink, the cylinder 55 that holds this needle 53, and the ink reservoir 57 that stores ink.
It has In the above wafer inspection apparatus, the present invention includes the following ink drying means. In this embodiment, the ink drying means 81 is a laser device attached to the ring insert 10 via a mounting device, and the laser device includes a laser oscillation device 83 and a wafer chip mounted on the wafer 40 attached to its tip 41 and a laser head 85 set on top of the laser head 85. The laser beam emitted from the laser oscillation device 83 is a continuous beam that is unfocused and condensed into a spot slightly larger than the mark formed on the wafer chip 41 by the input force. Note that the drying temperature can be controlled not only by the output of the laser beam but also by adjusting the focal length of the beam. This beam is directed to a mark formed on the wafer chip 41, and the wafer 40 held on the chuck 5o
As a result of the movement, the light beam moves relative to the surface of the wafer 4o and irradiates the position where the mark is formed. 87 is a control device that controls the laser oscillation device 83 of the laser device. The wafer inspection apparatus of this embodiment operates as follows. A signal is sent from the tester to the pad 42 of the wafer chip 41 through the probe 31 of the probe card 30 to test the electrical characteristics of the wafer chip, and if the result is defective, a signal is sent to the input input to identify the defective chip. A defective mark is displayed. Thereafter, the laser beam emitted from the laser oscillation device 83 is focused in an unfocused manner into a spot slightly larger than the mark formed on the wafer chip 41 by the above-mentioned input force, and is focused on the ink forming the mark. It irradiates and heats only that area, quickly drying the ink. The defect mark on the defective chip obtained in this process was very clear. Further, in the above embodiment, a laser device is used as the ink drying means 81, but a halogen lamp or the like may be used as appropriate as long as it can irradiate only the mark portion in a spot-like manner.

【Effect of the invention】

Since the wafer inspection apparatus of the present invention is constructed as described above, it is possible to accurately mark defective chips only on defective chips without contaminating surrounding good chips. In addition, since only the ink forming the mark is heated in a spot shape, it is possible to prevent good chips on the wafer from being heated and having an adverse effect, and the drying means is made to follow each chip at a predetermined time difference from the marking means. This allows for very efficient drying.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a main part showing an embodiment of a wafer inspection apparatus of the present invention, and FIG. 2 is a sectional view of a main part showing the state of defective markings in a conventional example. 40... Wafer 41... Wafer chip 81... Drying means 83... Laser oscillation device patent applicant Tokyo Electron Ltd. Figure

Claims (1)

[Claims] 1. Inspection means for selecting whether each chip on a wafer is good or defective; marking means for marking the selected defective chips with ink; and marked chips. A wafer inspection apparatus comprising: a drying means for drying ink by irradiating light from a light source in a spot shape only to a portion. 2. The wafer inspection apparatus according to claim 1, wherein the light source of the ink drying means is a laser device. 3. The wafer inspection apparatus according to claim 1, wherein the light source of the ink drying means is a halogen lamp. 4. The wafer inspection apparatus according to any one of claims 1 to 3, wherein the light irradiated onto the chip portion in a spot shape is condensed in a non-focused manner.