CN103646850A

CN103646850A - Method for marking atomic force probe (AFP) sample by FIB to realize positioning

Info

Publication number: CN103646850A
Application number: CN201310612744.4A
Authority: CN
Inventors: 倪亮
Original assignee: Shanghai Huali Microelectronics Corp
Current assignee: Shanghai Huali Microelectronics Corp
Priority date: 2013-11-26
Filing date: 2013-11-26
Publication date: 2014-03-19
Anticipated expiration: 2033-11-26
Also published as: CN103646850B

Abstract

The invention provides a method for marking an atomic force probe (AFP) sample by using an FIB to realize positioning. The method comprises the following steps that: a reference point is set on a sample; the sample is treated so that a metal layer can be obtained, and marking is performed at a position where the reference point is located through the FIB; and the sample is treated so that a contact layer can be obtained, and the sample is scanned through an atomic force probe (AFP) so that a marked position on the sample can be obtained, and a target unit can be found according to the reference point. The method of the invention is advantageous in simplicity, effectiveness and accurate positioning. With the method adopted, preparation difficulty of atomic force probe (AFP) fixed point test samples can be decreased; and nano probes and devices will not be damaged. The method is of great significance for an atomic force probe (AFP) fixed point test sample repetitive unit such as an SRAM region.

Description

Method with FIB marking location on AFP sample

Technical field

The present invention relates to a kind of localization method, relate in particular to a kind of method with FIB marking location on AFP sample.

Background technology

At semicon industry, the electrical failure analysis to chip, the especially chip product to 90nm and following processing procedure, need to use AFP(Atomic Force Probe, atomic force probe) carry out testing electrical property.

Its operation principle is: first, with nano-probe, at sample surfaces, scan, per sample surface height morphogenesis topographic map, the per sample big or small electrically figure that forms of micro-electric current (pico current) on surface; Then, according to topographic map, find out with electrical figure the target location acupuncture treatment that will test and carry out testing electrical property.Therefore,, if just need to locate near marking target location (mark) target location in fixed test repetitive (as SRAM region), then by the mark on topographic map and electrical figure, find target location to test.

Prior art is when beating mark, mainly to beat mark along BL and the WL direction of target location simultaneously, due to BL direction bit and the shared well (well) of target location bit district, well easily causes target location equipment (device) test result abnormal after being damaged by mark; Simultaneously this method mark damage position is more, and AFP nano-probe must sweep to accurately location of two mark simultaneously, has increased preparation difficulty and the positioning difficulty of AFP fixed test sample, also larger to nano-probe damage.

Summary of the invention

In view of the above problems, the invention provides a kind of method with FIB marking location on AFP sample.

The technical scheme that technical solution problem of the present invention adopts is:

By a method for FIB marking location on AFP sample, described sample comprises metal level and contact layer, on described sample, has target location, said method comprising the steps of:

Step 1 is set reference point on described sample, the some displacements in target location of the described sample of described reference point distance;

Step 2, to metal level, passes through FIB marking at the reference point place of described sample by described sample treatment, and described mark has given shape;

Step 3, arrives contact layer by described sample treatment, by described AFP scanning samples, and the position that draws sample mark, and find described target unit according to described some displacements.

Preferably, reference point 2 of target locations bit described in distance on horizontal line in described step 1.

Preferably, in step 2 described in be labeled as through orthogonal two line segments of described reference point.

Preferably, described sample adopts 65/55nm processing procedure.

Preferably, the width of described mark is less than the needle point diameter of described AFP.

Preferably, the needle point diameter of described AFP is 130nm.

Preferably, the line segment that is labeled as two each long 5 μ m, wide 0 μ m, dark 1.2 μ m in described step 2.

Preferably, described step 3 by described AFP scanning samples, draws topographic map and electrically schemes, finding the position of sample mark on figure.

Technique scheme tool has the following advantages or beneficial effect:

Technical scheme of the present invention is simple effectively, accurate positioning, has reduced the preparation difficulty of AFP fixed test sample, to nano-probe and device, can not cause damage, and AFP fixed test sample repetitive (as SRAM region) is had to very important meaning.

Accompanying drawing explanation

With reference to appended accompanying drawing, to describe more fully embodiments of the invention.Yet appended accompanying drawing only, for explanation and elaboration, does not form limitation of the scope of the invention.

Fig. 1 is the schematic diagram of the reference point in the embodiment of the present invention;

Fig. 2 is the mark schematic diagram of 150 times of OM images forming in the embodiment of the present invention;

Fig. 3 is AFP landform schematic diagram in the embodiment of the present invention;

Fig. 4 is the electrical schematic diagram of AFP in the embodiment of the present invention.

Embodiment

By specific embodiment, method of the present invention is elaborated below.

A kind of method with FIB marking location on AFP sample of the embodiment of the present invention, sample comprises metal level and contact layer, has target location on sample, method comprises the following steps:

Step 1 as shown in fig. 1, is set reference point 2 on sample, and reference point 2 is apart from the some displacements in target location 1 of sample, preferably along 2, WL direction interval bit;

Step 2, as shown in Figure 2, by sample treatment, to metal level, preferably M2 (metal two) layer, passes through FIB marking at reference point 2 places of sample, and mark has given shape; Preferably by adjusting FIB parameter (take 65/55nm sample as example, long 5 μ m, wide 0 μ m, dark 1.2 μ m) marking;

Step 3, by sample treatment, to contact layer, logical AFP scanning samples draws topographic map as shown in Figure 3 and Figure 4 and electrically schemes, thereby draw the position of sample mark, and the position of reference point 2, and find target unit 1 according to some displacements, then pin is moved on to target location scan and test.

Compared with prior art, in the middle of this method employing target location and mark, along 2, WL direction interval bit, so neither can hurt the device of target location, also allow the fixed test of AFP more precisely simple.The about 56nm of width of Mark, much smaller than nano-probe needle point diameter 130nm, so can not hurt the nano-probe of scanning.

The inventive method is simply effective, and accurate positioning has reduced the preparation difficulty of AFP fixed test sample, to nano-probe and device, can not cause damage, and AFP fixed test sample repetitive (as SRAM region) is had to very important meaning.

For a person skilled in the art, read after above-mentioned explanation, various changes and modifications undoubtedly will be apparent.Therefore, appending claims should be regarded whole variations and the correction of containing true intention of the present invention and scope as.Within the scope of claims, scope and the content of any and all equivalences, all should think and still belong to the intent and scope of the invention.

Claims

1. by a method for FIB marking location on AFP sample, described sample comprises metal level and contact layer, on described sample, has target location, it is characterized in that, said method comprising the steps of:

2. the method with FIB marking location on AFP sample as claimed in claim 1, is characterized in that, reference point 2 of target locations bit described in distance on horizontal line in described step 1.

3. the method with FIB marking location on AFP sample as claimed in claim 1, is characterized in that, is labeled as through orthogonal two line segments of described reference point described in step 2.

4. the method with FIB marking location on AFP sample as claimed in claim 3, is characterized in that, described sample adopts 65/55nm processing procedure.

5. the method with FIB marking location on AFP sample as claimed in claim 1, is characterized in that, the width of described mark is less than the needle point diameter of described AFP.

6. the method with FIB marking location on AFP sample as claimed in claim 5, is characterized in that, the needle point diameter of described AFP is 130nm.

7. the method with FIB marking location on AFP sample as claimed in claim 6, is characterized in that, the line segment that is labeled as two each long 5 μ m, wide 0 μ m, dark 1.2 μ m in described step 2.

8. the method with FIB marking location on AFP sample as claimed in claim 1, is characterized in that, described step 3, by described AFP scanning samples, draws topographic map and electrical figure, finds the position of sample mark on figure.