CN101452027B

CN101452027B - Wafer shipment quality guarantee detecting method

Info

Publication number: CN101452027B
Application number: CN2007101715730A
Authority: CN
Inventors: 康盛; 王明珠; 黄臣; 吕秋玲
Original assignee: Semiconductor Manufacturing International Shanghai Corp
Current assignee: Semiconductor Manufacturing International Shanghai Corp
Priority date: 2007-11-30
Filing date: 2007-11-30
Publication date: 2011-08-03
Anticipated expiration: 2027-11-30
Also published as: CN101452027A

Abstract

The invention discloses a wafer shipment quality assurance detecting method, relating to detecting technology of the semiconductor field. In the prior detecting method, the detected area and position are fixed, the chip on the outside of the detected are is not found in time. The inventive detecting method comprises: dividing the wafer into a plurality of area, each area including a plurality of chips, wherein the number of the chip in each area is the same or differs by one at most; determining the least number of the chip required to be detected according to the quality level of the wafer; according to the least number of the chip required to be detected, randomly selecting the chip for detecting in the area, wherein the number of the chip in each area is the same or differs by one at most. According to the inventive method, the chip is detected randomly, under the condition of not increasing the number of the chip, more wafer area is detected, through sampling more wafer, the chip in much more area is detected, thereby increasing accuracy of the detecting result.

Description

The shipment quality guarantee detecting method of wafer

Technical field

The present invention relates to the characterization processes of semiconductor applications, specifically, relate to a kind of shipment quality guarantee (outgoing quality assurance is called for short " OQA ") detection method of wafer.

Background technology

At present, the OQA of wafer detects and only the chip in the fixed area of wafer is detected usually.Fig. 1 is the sampling figure that adopts wafer when having detection method now.The step that this detection method adopts is: at first select 5 square zones at upper and lower, left and right, the middle part of wafer, each square zone has the detection chip (die) of equal number.How much deciding according to the chip count on the wafer of each interior detection chip in zone in the wafer shown in Figure 1, comprises 16 detection chip in each zone.Adopt optical microscope (OM) or other checkout equipments that the detection chip of selecting is detected then, decide this whether can shipment according to bad sheet quantity occurring.

Adopt conventional detection to have certain limitation, because, all can not find the defective on the extra-regional chip of square, particularly systematic defective no matter with what wafers of machine testing, as the defective that repeats in the fixed position, and this position is not in surveyed area.Cause the reason of chip defect varied, so the chip of any position all defective might occur on the wafer.Adopt conventional detection, can miss the defective that appears at the extra-regional chip of square, finally cause customer complaint.

Summary of the invention

In view of this, the technical matters that the present invention solves provides a kind of shipment quality guarantee detecting method of wafer, and it can detect the random defect on the wafer effectively.

For solving the problems of the technologies described above, the invention provides a kind of shipment quality guarantee detecting method of new wafer.This detection method comprises the steps: wafer zoning territory is comprised several chip in each zone that wherein the number of chips in each zone equates or differs 1 at the most; Determine the minimum number of the chip that needs detect according to the quality grade of wafer, wherein the number of chips that comprises on the wafer is many more, and the quality grade of wafer is high more, needs the quantity of the chip that detects also many more; The minimum number of the chip of Jian Ceing as required, the picked at random chip detects in described zone, and wherein the number of chips that detects in each zone equates or differs 1 at the most.

Compared with prior art, detection method provided by the invention is to select detection chip at random, under the situation that does not increase detection chip quantity, has detected bigger wafer area; By to the sampling of a plurality of wafers, realized detection to the most of regional chip of wafer, improved the degree of accuracy of testing result, avoided or reduced and given the client problematic chip shipment.

Description of drawings

Fig. 1 is the sampling figure that adopts wafer when having detection method now.

Fig. 2 is the synoptic diagram of the dividing region of wafer when adopting detection method of the present invention.

Fig. 3 is the sampling figure of wafer when adopting detection method of the present invention.

Embodiment

Shipment quality guarantee detecting method one embodiment to wafer of the present invention is described below in conjunction with accompanying drawing, in the hope of purpose, specific structural features and the advantage of further understanding its invention.

Detection method step provided by the invention is as follows, at first will detect wafer zoning territory, comprises several chip in each zone, and wherein the number of chips in each zone differs 1 at the most.See also Fig. 2, the detection wafer of present embodiment has 332 chips, is divided into 7 roughly the same zones 1., 2., 3., 4., 5., 6., 7., 8., 9., during division, at first from crystal round fringes, select chip in the direction of arrows one by one, every selection 47 or 48 chips are formed a zone.

Then, according to the quality grade that detects wafer, come definite quantity that needs the detection chip of detection, wherein quality grade determines that by the chip count that wafer comprises chip count is high more, and quality grade is high more, and the quantity of need detection chip is also just many more accordingly.In the present embodiment, described quality grade is accepted grade (Acceptable Quality Level is called for short " AQL ") 0.65 according to quality and is divided quality grade, shown in the subordinate list 1 of back.Detection wafer shown in Figure 2 has 332 chips, belongs to the grade 2 in the table 1, so minimumly will detect 80 detection chip, in subsequent detection, if 1 bad sheet is arranged, belongs to tolerance interval, can be by shipment; If have 2 to reach with last bad sheet, then needing to return the workshop can not shipment.

Next, select chip as detection chip in each zone at random, the detection chip in each zone differs 1 at the most.In the present embodiment, in each zone, select 11 or 12 chips to detect as detection chip.Fig. 3 is a kind of sampling figure of picked at random, and the chip that has pentagram to indicate is exactly a detection chip.

In detection method of the present invention, choosing of detection chip is at random in each zone, the detection wafer of sampling, repeatedly picked at random in same batch, can realize that most or all of chips detect on the wafer to detecting, thereby improve the degree of accuracy of testing result.

In addition, carry out afterwards if detection method of the present invention is the circuit function test (Circuit Probing is called for short " CP test ") at wafer, above-mentioned zone is divided and is selected chip only to carry out at the good sheet after the CP test at random, can save the time of detection like this, raise the efficiency.

Foregoing description; only being the specific descriptions to preferred embodiment of the present invention, is not to any qualification of the present invention, for the person of ordinary skill of the art; can carry out simple modification, interpolation, conversion according to above-mentioned disclosure, and all belong to the content of protecting in claims.

Table 1

Quality grade	Chip count on the wafer	The minimum quantity of sampling quantity of each wafer	Bad sheet quantity-acceptance	Bad sheet quantity-return
					1	1-280	20	0	1
2	281-1200	80	1	2
					3	1201-3200	125	2	3
4	3201-10000	200	3	4
					5	10001-35000	315	5	6
6	35001-150000	500	7	8
					…	…	…	…	…

Claims

1. the shipment quality guarantee detecting method of a wafer is characterized in that, described detection method comprises the steps:

With wafer zoning territory, comprise several chip in each zone, wherein the number of chips in each zone is identical or differ 1 at the most;

Determine the minimum number of the chip that needs detect according to the quality grade of wafer, wherein the number of chips that comprises on the wafer is many more, and the quality grade of wafer is high more, needs the quantity of the chip that detects also many more;

The minimum number of the chip of Jian Ceing as required, the picked at random chip detects in described zone, and wherein the number of chips that detects in each zone is identical or differ 1 at the most.

2. the shipment quality guarantee detecting method of wafer as claimed in claim 1, it is characterized in that: if this detection method is applied to after the circuit function test of wafer, described with wafer zoning territory and in described zone the picked at random chip detect only at dividing and detect by the good chip after the circuit function test.

3. the shipment quality guarantee detecting method of wafer as claimed in claim 1 is characterized in that: describedly with wafer zoning territory be: from crystal round fringes, adopt the mode of the chip of choosing some one by one to divide.