CN103645075B

CN103645075B - Manufacturing method for TEM (Transmission Electron Microscope) sample and TEM sample

Info

Publication number: CN103645075B
Application number: CN201310625537.2A
Authority: CN
Inventors: 陈强; 邱燕蓉
Original assignee: Shanghai Huali Microelectronics Corp
Current assignee: Shanghai Huali Microelectronics Corp
Priority date: 2013-11-28
Filing date: 2013-11-28
Publication date: 2017-04-12
Anticipated expiration: 2033-11-28
Also published as: CN103645075A

Abstract

The invention provides a manufacturing method for a TEM (Transmission Electron Microscope) sample and a TEM sample formed by adopting the manufacturing method. The method comprises the following steps: a sample is provided, wherein the sample is provided with a target region and the sample comprises a silicon substrate and a chip material layer covering the silicon substrate; the sample is subjected to a section grinding process; the distance from an edge of the sample subjected to the section grinding to the target region is 2-10 microns; a single-side large pit is formed in the sample subjected to the section grinding and the thickness of the sample subjected to the section grinding is thinned to 1-3 microns; the chip material layer covering the silicon substrate is removed, and the sample is kept; plane sampling is carried out on the thinned sample by adopting an FIB (Focused Ion beam) method to form the TEM sample. According to the TEM sample manufactured by adopting the method provided by the invention, dislocations of all positions on the silicon substrate can be clearly observed from the plane TEM sample and the influences caused by metal silicide are avoided.

Description

The preparation method and its TEM sample of TEM sample

Technical field

The present invention relates to technical field of semiconductors, the preparation method of more particularly to a kind of TEM sample and using the making side The TEM sample that method is obtained.

Background technology

The material of Semiconductor substrate is usually the structure of monocrystalline silicon, but in the various technical process carried out to Semiconductor substrate In some defects can be produced inside Semiconductor substrate（Such as dislocation defects）, these defects can cause the semiconductor for ultimately forming The even whole chip failure of device.

In prior art, those skilled in the art utilize transmission electron microscope（TEM）Method sample is observed, The sample is usually using using section grinding or flat focus ion beam（FIB）Method sample silicon substrate is made Formed.But the TEM sample that prior art is formed is only used for observing small dislocation especially severe or in channels, and For in source and drain areas nickle silicide etc.（NiSi）Small dislocation below level, then can be due to NiSi when TEM is observed Disturb and cannot differentiate.It is therefore desirable to being improved to the preparation method of existing TEM sample so that the TEM sample of making The defect of each position on sample can clearly be observed, it is to avoid the impact that metal silicide is caused to TEM sample observation.

The content of the invention

The TEM sample that the problem that the present invention is solved is to provide a kind of preparation method of TEM and is made using the method, can Clearly observe the dislocation of each position on silicon substrate in plane TEM sample, it is to avoid the shadow that metal silicide is caused Ring.

In order to solve the above problems, a kind of preparation method of TEM sample of the invention, including：

Sample is provided, there is target area in the sample, the sample is silicon substrate and the chip material for covering thereon Layer；

Section grinding technics, the edge of the sample after the grinding of section and the distance of the target area are carried out to the sample For 2-10 microns；

Unilateral hollow place is formed on sample after the grinding of the section, the thickness of the sample after the section grinding is thinning to be 1-3 microns;

Remove the chip material layer covered on silicon substrate, keeping sample；

Plane sample preparation is carried out to the sample after thinning using FIB methods, TEM sample is formed.

Alternatively, the sample on the removal silicon substrate the step of chip material layer of covering after the grinding of the section Formed after the step of unilateral hollow place is formed on product.

Alternatively, the chip material layer covered on silicon substrate that removes is to be removed using acid solution.

Alternatively, the acid solution is hydrofluoric acid.

Alternatively, the thickness range of the TEM sample of formation is 0.1-0.3 microns.

Alternatively, also include：After the chip material layer that will be covered on silicon substrate is removed, surface clean is carried out to sample Step.

Correspondingly, the present invention also provides the TEM sample that a kind of utilization methods described makes, the thickness model of the TEM sample Enclose for 0.1-0.3 microns.

Compared with prior art, it is an advantage of the current invention that：

The TEM sample made using the method for the present invention can clearly observe the defect of each position on sample, keep away Exempt from the impact that metal silicide is caused to TEM sample observation, the method for the present invention can be used for fixed point analysis or non-fixed point analysis.

Description of the drawings

Fig. 1 is the TEM sample preparation method schematic flow sheet of the present invention；

Fig. 2-Fig. 4 is the TEM sample preparation method cross-sectional view of one embodiment of the present invention；

Fig. 5 is the overlooking the structure diagram of the sample shown in Fig. 2.

Specific embodiment

The TEM sample that prior art is formed is only used for observing small dislocation especially severe or in channels, and For in source and drain areas nickle silicide etc.（NiSi）Small dislocation below level, then can be due to NiSi when TEM is observed Disturb and cannot differentiate.It is therefore desirable to being improved to the preparation method of existing TEM sample so that the TEM sample of making The defect of each position on sample can clearly be observed, it is to avoid the impact that metal silicide is caused to TEM sample observation.

In order to solve the above problems, a kind of preparation method of TEM sample of the invention refer to of the invention shown in Fig. 1 TEM sample preparation method schematic flow sheet, the preparation method of the TEM sample includes：

Step S1, there is provided sample, has target area in the sample, the sample is silicon substrate and the core for covering thereon The sheet material bed of material；

Step S2, section grinding technics, the edge and the target area of the sample after the grinding of section are carried out to the sample The distance in domain is 2-10 microns；

Step S3, forms unilateral hollow place, the thickness of the sample after the section grinding on the sample after the grinding of the section Degree is thinning for 1-3 microns;

Step S4, removes the chip material layer covered on silicon substrate, keeping sample；

Step S5, plane sample preparation is carried out using FIB methods to the sample after thinning, forms TEM sample.

Technical scheme is described in detail with reference to specific embodiment.In order to this is better described Bright technical scheme, shows incorporated by reference to the TEM sample preparation method cross-section structure of the one embodiment of the present invention shown in Fig. 2-Fig. 4 It is intended to.

First, refer to Fig. 2, and combine Fig. 5, Fig. 5 be Fig. 2 shown in sample overlooking the structure diagram, execution step S1, there is provided sample 10, has target area 20 in the sample 10, the sample 10 includes silicon substrate and on silicon substrate Chip material layer.Then, please continue to refer to Fig. 2, execution step S2 carries out section grinding technics, section to the sample 10 The edge of the sample 10 after grinding is 2-10 microns with the scope apart from D of the target area 20.

Then, please continue to refer to Fig. 2, execution step S2 forms unilateral hollow place on the sample 10 after the grinding of the section, The thickness of the sample 10 after the section grinding is thinning for 1-3 microns;

Then, refer to Fig. 3 and combine Fig. 2, on the sample 10 after the grinding of the section the step of hollow place of formation one side Afterwards, execution step S4, removes the chip material layer 30 covered on silicon substrate, keeping sample 10.As one embodiment, The chip material layer 30 removed on sample 10 is to be removed using acid solution.In the present embodiment, the acid solution is hydrogen Fluoric acid.As preferential embodiment, after the chip material layer on sample 10 is removed, the step of surface clean is carried out to sample 10 Suddenly.

Then, Fig. 4 is refer to, and execution step S5, plane sample preparation is carried out to the sample 10 after thinning using FIB methods, TEM sample is formed, the thickness range of the TEM sample of formation is 0.1-0.3 microns.

To sum up, the TEM sample for being made using the method for the present invention can clearly observe lacking for each position on sample Fall into, it is to avoid the impact that metal silicide is caused to TEM sample observation, the method for the present invention can be used for fixed point analysis or non-fixed point Analysis.

Therefore, above-mentioned preferred embodiment technology design only to illustrate the invention and feature, its object is to allow and are familiar with this The personage of item technology will appreciate that present disclosure and implement according to this, can not be limited the scope of the invention with this.It is all The equivalence changes made according to spirit of the invention or modification, all should be included within the scope of the present invention.

Claims

1. a kind of preparation method of TEM sample, it is characterised in that include：

Sample is provided, there is target area in the sample, the sample is silicon substrate and the chip material layer for covering thereon；

Section grinding technics is carried out to the sample, the edge of the sample after the grinding of section is 2- with the distance of the target area 10 microns；

Unilateral hollow place is formed on sample after the grinding of the section, the thickness of the sample after the section grinding is thinning for 1-3 Micron;

Remove the chip material layer covered on silicon substrate, keeping sample；

2. the preparation method of TEM sample as claimed in claim 1, it is characterised in that the institute covered on the removal silicon substrate Formed after the step of the step of stating chip material layer forms unilateral hollow place on the sample after the grinding of the section.

3. the preparation method of TEM sample as claimed in claim 1, it is characterised in that the institute covered on the removal silicon substrate It is to be removed using acid solution to state chip material layer.

4. the preparation method of TEM sample as claimed in claim 3, it is characterised in that the acid solution is hydrofluoric acid.

5. the preparation method of TEM sample as claimed in claim 1, it is characterised in that the thickness range of the TEM sample of formation is 0.1-0.3 microns.

6. the preparation method of TEM sample as claimed in claim 1, it is characterised in that also include：By the silicon substrate overlying After the chip material layer of lid is removed, the step of carry out surface clean to sample.

7. the TEM sample for being made using claim 1 methods described, it is characterised in that the thickness range of the TEM sample is 0.1-0.3 microns.