JPH04170039A - Method for marking semiconductor device pellet - Google Patents

Abstract

PURPOSE:To analyze failure without damaging or staining a chuck mechanism and marking even by a mask-type card method by marking a defective pellet using UV light. CONSTITUTION:At the pre-process of a P/W check process, special resist 2 which becomes positive by electronic beam exposure and becomes negative by UV exposure is coated on a wafer and the resist 2 is left only at the center of a pellet 1 by the electronic beam exposure. Then, at electric testing process, when a check result is judged defective, UV light is emitted from a UV light source 7 through an optical fiber cable 6. The UV light is condensed using a condensing lens 4, irradiate the resist 2 so as to expose and develop and only the resist 2 is remained on the defective pellet 1. Thus, the failure analysis and the mismeasurement of the defective pellet is rechecked and marking by a mask-type card method is allowed.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for marking semiconductor device pellets, and in particular, the present invention relates to a method for marking semiconductor device pellets, and in particular, the present invention relates to a method for marking semiconductor device pellets. This invention relates to a method for marking semiconductor device pellets to mark them as defective.

[Conventional technology]

Conventionally, there are three methods for marking defective pellets in a pellet electrical property test (hereinafter referred to as P/W check) process. The first method is to scratch the surface of the pellet with a piano wire or sapphire needle, the second method is to apply ink, etc. to the surface of the pellet, and the third method is to destroy the surface of the pellet with a laser beam. It's a method.

[Problem to be solved by the invention]

The three methods described above have the disadvantage of damaging or staining the chuck mechanism that fixes the wafer in the case of pellets located on the outer periphery of the wafer.Furthermore, the pellets after marking have to be analyzed for failure or re-P/W. If you want to check it, it has the disadvantage that the internal elements or circuits have already been destroyed or deteriorated, and it is impossible to perform electrical failure analysis or re-check the P/W to correct erroneous measurements. ing.

Furthermore, in the three methods described above, marking is possible if the probe card method is used in which the measurement probe is directly connected to each bonding butt;
As shown in a) and (b), the mask-type card method in which a probe for contacting the bonding butt is embedded in a transparent mask 9 has a fatal drawback in that marking is not possible. are doing.

As a defect removal method using a mask type card method, there is a method of dropping the address of a defective pellet into an FDD and later removing the defective pellet according to the address, but this method has the disadvantage that the management method becomes complicated.

An object of the present invention is to provide a method for marking semiconductor device pellets, which allows failure analysis of defective pellets and rechecking of erroneous measurements without damaging or staining the chuck mechanism, and which also enables marking using a mask type card method. There is a particular thing.

[Means to solve the problem]

The method for marking semiconductor device pellets of the present invention includes:
Before the electrical check process of the semiconductor device pellet at the wafer stage, a special resist that is positive in electron beam exposure and negative in UV exposure is coated on the wafer, and the central part of the semiconductor device pellet is exposed by the electron beam exposure. The step of leaving the resist only on the surface of the pellet and irradiating the UV light to the defective pellet determined as defective in the electrical check step leaves the resist and determines the pellet to be defective.

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a schematic diagram of an example of a semiconductor device pellet marking apparatus used in an embodiment of the present invention.

As shown in FIG. 1, the semiconductor device pellet marking apparatus includes a UV light source 7. Optical fiber cable 6, condensing lens 4 and lens height adjuster 5
It is composed of.

Next, its operation will be explained. First, in the pre-process of the P/W check process, electron beam exposure is performed on the wafer to produce positive and
In UV exposure, a special negative resist is applied, and by electron beam exposure, resist 2 is applied only to the center of pellet 1.
leave.

Next, in the P/W check step, if the check result is determined to be defective, UV light is emitted from the UV light source 7 through the optical fiber cable 6.

This UV light is focused using a condensing lens 4, and is irradiated onto the resist 2, thereby exposing it to light. When the size of the pellets l changes, the height of the condensing lens 4 is adjusted by turning the lens height adjuster 5.

The P/W check is performed as described above, and after completion, development is performed to leave the resist 2 only on the defective pellets 1, thereby making it possible to distinguish between good and defective pellets 1.

〔Effect of the invention〕

As explained above, the present invention uses UV light to mark defective pellets without damaging or staining the chuck mechanism that fixes the wafer, and even with marking, there is no damage to internal elements or circuits. Alternatively, defective pellets marked after P/W check can be analyzed without causing deterioration, and pellets that have been incorrectly judged due to a defect in the measurement system can be rechecked and shipped as non-defective. effective.

Furthermore, there is a great effect that marking can be performed even if the measurement probe is of a mask type card type.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram of an example of a marking device for semiconductor device pellets used in an embodiment of the present invention, and FIG.
) and (b) are a side view and a plan view of an example of a mask type card. DESCRIPTION OF SYMBOLS 1... Pellet, 2... Resist, 3... Mass type card, 4... Condenser lens, 5... Lens height adjuster, 6... Optical fiber cable, 7... UV light source, 8... measurement probe, 9... transparent mask.

Claims (1)

[Claims] Before the electrical check process of the semiconductor device pellet at the wafer stage, a special resist that is positive in electron beam exposure and negative in UV exposure is coated on the wafer, and the central part of the semiconductor device pellet is exposed by the electron beam exposure. Marking of semiconductor device pellets, characterized by a step of leaving the resist only in the electrical check step, and irradiating the UV light to the defective pellets determined to be defective in the electrical check step, leaving the resist and determining the pellets to be defective. Method.