CN101220477A - Corrosive agent and corrosion method for II-VI family semiconductor material line defect display - Google Patents

Abstract

The invention discloses a corrosive agent which is used for showing the dislocation of II-VI group semiconductor materials and the corrosive agent is provided with the component ratio of 80ml: 6 to 10ml: 10 to 15ml: 0 to 5ml: 5.1g: 2.0 to 7.0g of H2O to HCl to HNO 3 to HF to K2Cr2O7 to CrO3; wherein, the II-VI group semiconductor materials are ZnyCd1-yTe materials and Hg1-xCdxTe thin film materials which develop by taking the ZnyCd1-yTe materials as the substrate extension; the corrosion method comprises the pretreatment of the eroded samples, the dislocation erosion and the post treatment of the eroded samples; compared with two present common Schaake and Chen corrosive agents specially used for showing the dislocation of the Hg1-xCdxTe thin film materials, the invention has the advantages of bigger shape of a corrosive pit and clear rules and background, and showing the dislocation corrosive pit of the substrate materials Cd1-yZnyTe, which has great significance in the study of the dislocation corresponding relations of the extension and the substrate.

Description

Be used for etching reagent and caustic solution that II-VI family semiconductor material dislocation shows

Technical field

The present invention relates to II-VI family semiconductor material, specifically be meant a kind of Te-Cd-Hg (Hg that is used for _1-xCd _xTe) epitaxial thin film material and tellurium zinc cadmium (Cd _1-yZn _yTe) etching reagent and the caustic solution of the demonstration of substrate body material dislocation.

Background technology

Hg _1-xCd _xTe is a kind of extremely important infrared acquisition material, usually by Cd _1-yZn _yExtension Hg on the Te substrate _1-xCd _xThe Te film, the dislocation desity (EPD) of therefore studying its material has great importance.Disclose Cd at present _1-yZn _yTe body material and Hg _1-xCd _xThe etching reagent of Te thin-film material dislocation desity has a variety of.For Hg _1-xCd _xThe etching reagent commonly used of Te thin-film material has two kinds, a kind ofly is: H ₂O: HCl: CrO ₃=5ml: 1ml: 1.67g sees H.F.Schaake, A.J.Lewis, Mater.Res.Soc.Symp.Proc. (USA) 14,301 (1983); Another kind is: H ₂O: HCl: HNO ₃: K ₂Cr ₂O ₇=80ml: 10ml: 20ml: 8g sees J.S.Chen, US Patent No.4.897.152, (1990), wherein Chen is acknowledged as present Hg _1-xCd _xThe standard etching reagent that the Te dislocation desity shows.These two kinds of etching reagent respectively have relative merits.

The advantage of Chen etching reagent: corrosion pit type rule

The shortcoming of Chen etching reagent: 1 hole type is little, and the length of side is about 1.5um, can only add up down for 1000 times with opticmicroscope; 2 backgrounds " oxidation " are serious, be unfavorable for the identification of corrosion pit, remove microscopical differential interference beam splitting prism (Normaski) and can strengthen corrosion pit and background contrasts, but the shape characteristic in the background also can be covered, water stain vestige after the corrosion appears simultaneously, and " attractive in appearance " of corrosion pit image observed in influence; The dislocation etch pit of 3 corrosion samples is divided into two classes: C1 and C2, sees Yang Jianrong, Chen Xinqiang andHe Li, SPIE, 4795,76 (2002), Cao Xiuliang and Yang Jianrong, Chinese Laser﹠amp; Infrared, 35,45 (2005).C1 is the black corrosion pit of wedge angle, it is with the corrosion pit unanimity of etching reagent effect of the present invention cited below, and C2 is the triangular form corrosion pit of white circular arc angle, and this class corrosion pit is that we do not add up at present, its mechanism of production is unclear, the also not relevant report of document; 4 couples of Cd _1-yZn _yThe Te substrate has very strong oxygenizement, can make the substrate surface blackening.

The advantage of Schaake etching reagent: the clear light of background, corrosion pit and background are easy to distinguish.

The shortcoming of Schaake etching reagent: 1, the hole type is very irregular, and is not of uniform size; 2, corrosion pit is divided into two classes: S1 and S2.S1 is that the hole type is very irregular, not of uniform size; S2 is the dot in the background, and it doesn't matter for its density and S1, and the general dislocation desity order of magnitude is 1 * 10 ⁴/ cm ²To 1 * 10 ⁷/ cm ²Between, about also not relevant report in the mechanism of production document of S2; 3, to Cd _1-yZn _yLight behind the Te substrate etching, but do not produce corrosion pit.

Summary of the invention

The objective of the invention is to find a kind of Chen of possessing and two kinds of etching reagent advantages of Schaake and avoid the novel etching reagent of its shortcoming and show Hg with this etching reagent _1-xCd _xThe method of Te film dislocation etch pit, this etching reagent can be to Cd simultaneously _1-yZn _yThe dislocation corrosion of Te substrate produces good effect.

A kind of etching reagent that II-VI family semiconductor material dislocation shows that is used for of the present invention, it is characterized in that: the proportioning of etching reagent is:

H ₂O∶HCl∶HNO ₃∶HF∶K ₂Cr ₂O ₇∶CrO ₃＝80ml∶6-10ml∶10-15ml∶0-5ml∶5.1g∶2.0-7.0g。

A kind of caustic solution that II-VI family semiconductor material dislocation shows that is used for of the present invention, its step is as follows:

1. The pretreatment is corroded

It is to remove the wax and the grease of sample surfaces in the ebullient trieline that the sample that is corroded is placed on temperature; Blow the dust and the chip of sample surfaces then with nitrogen gun; Use 0.2%Br-CH at last ₂The zone of oxidation on surface was removed in the corrosion of OH corrosive fluid in 10 seconds.

2. dislocation corrosion

The sample that is corroded is placed in the quartzy hanging basket of hollow out,, repeated this process 2-5 minute in the etching reagent that with hand control quartzy hanging basket was immersed, proposes above-mentioned preparation in 10 seconds 4-5 time.

3. the aftertreatment of sample is corroded

With the deionized water rinsing of the big flow velocity sample that is corroded, the time is greater than 5 minutes, to guarantee the corrosive fluid cleaning down blowing sample surfaces with nitrogen gun then totally with anti-oxidation, dries up up to the water sample surfaces.

Advantage of the present invention:

1 not oxidation of sample surfaces, the corrosion pit background is very clean, clear, is beneficial to the identification of corrosion pit;

The 2 corrosion pit type length of sides are about 4um, therefore adopt opticmicroscope to observe down at 200 times, and this etch-pit density statistics for low dislocation is useful;

3 can be to Hg _1-xCd _xTe epitaxial thin film material and Cd _1-yZn _yTe substrate body material can produce dislocation corrosion, and this corresponding relation for both dislocation etch pits of research is significant.

Description of drawings

Fig. 1 is Cd _0.04Zn _0.96The Hg of Te substrate rheotaxial growth _0.7Cd _0.3The Te thin-film material, Hg _0.7Cd _0.3Te (111) B face dislocation corrosion figure amplifies 1000x, is the Chen etching reagent, etching time 5min, room temperature.Be the photo when not removing Normaski, can see C1 and C2 class defective and deposit that corrosion pit length of side 1.5um can not observe under low-power microscope.This is that employing Chen etching reagent has been good photo.

Fig. 2 is Cd _0.04Zn _0.96The Hg of Te substrate rheotaxial growth _0.7Cd _0.3The Te thin-film material, Hg _0.7Cd _0.3Te (111) B face dislocation corrosion figure amplifies 1000x.Etching reagent is Schaake, etching time 2.5min, room temperature.It is photo when not removing Normaski.Can see S1 and S2 class defective and deposit.Background is clear, clean, but S1 class corrosion pit is very irregular, and not of uniform size, and less S1 class can't be distinguished with the S2 class.

Fig. 3 is etching reagent and preparation precedence diagram.

Fig. 4 (a) is Hg _0.7Cd _0.3Te (111) B face dislocation corrosion Figure 100 0x;

Fig. 4 (b) is Hg _0.7Cd _0.3Te (111) B face dislocation corrosion Figure 200 x;

Fig. 5 is Hg _0.7Cd _0.3Te (111) B face dislocation corrosion Figure 100 0x;

Fig. 6 is Hg _0.7Cd _0.3Te (110) face dislocation corrosion Figure 100 0x;

Fig. 7 is Zn _0.04Cd _0.96Te (111) B face dislocation corrosion Figure 100 0x;

Fig. 8 is Zn _0.04Cd _0.96Te (211) B face dislocation corrosion Figure 100 0x.

Embodiment

Below in conjunction with drawings and Examples the specific embodiment of the present invention is described in further detail:

Etching reagent comprises: H ₂O, HCl, HNO ₃, HF, K ₂Cr ₂O ₇, CrO ₃The mixing of each composition of etching reagent priority placement order routinely is followed successively by: H ₂O → HNO ₃→ CrO ₃→ K ₂Cr ₂O ₇→ HCl → HF, stirring at room temperature gets final product, and sees Fig. 3.

Implement 1

The sample that is corroded is Zn _0.04Cd _0.96The Hg of Te substrate rheotaxial growth _0.7Cd _0.3The Te thin-film material shows Hg _0.7Cd _0.3The dislocation of Te film.The etching reagent proportioning is: H ₂O: HCl: HNO ₃: K ₂Cr ₂O ₇: CrO ₃=80ml: 8ml: 12ml: 5.1g: 2.5g.At room temperature, the sample that is corroded is placed in the quartzy hanging basket of hollow out, in the etching reagent that hanging basket was immersed, propose above-mentioned preparation in 10 seconds with hand control 4 times, this process is 2.5 minutes continuously.See Fig. 4 (a) and Fig. 4 (b) dislocation corrosion figure, the sample crystal face is (111) B face, belongs to low etch-pit density sample.Because the etch-pit density order of magnitude is 10 ³-10 ⁴/ cm ²Between, so can not add up etch-pit density under the opticmicroscope 1000X, but can under 200X, add up, having improved the confidence level of its numerical value greatly, this is that the Chen etching reagent is irrealizable, its dislocation desity (EPD)=5.0 * 10 ³/ cm ²

Implement 2

The sample that is corroded is Zn _0.04Cd _0.96The Hg of Te substrate rheotaxial growth _0.7Cd _0.3The Te thin-film material shows Hg _0.7Cd _0.3The dislocation of Te film.The etching reagent proportioning is: H ₂O: HCl: HNO ₃: K ₂Cr ₂O ₇: CrO ₃=80ml: 8ml: 12ml: 5.1g: 2.5g.At room temperature, the sample that is corroded is placed in the quartzy hanging basket of hollow out, in the etching reagent that hanging basket was immersed, propose above-mentioned preparation in 10 seconds with hand control 4 times, this process is 2.5 minutes continuously.See Fig. 5 dislocation corrosion figure, sample is (111) B face, belongs to high EPD sample, its EPD=2.0 * 10 ⁵/ cm ²

Implement 3

The sample that is corroded is Zn _0.04Cd _0.96The Hg of Te substrate rheotaxial growth _0.7Cd _0.3The Te thin-film material shows Hg _0.7Cd _0.3The dislocation of Te film, cleavage surface (110) face.The etching reagent proportioning is: H ₂O: HCl: HNO ₃: HF: K ₂Cr ₂O ₇: CrO ₃=80ml: 8ml: 12ml: 5ml: 5.1g: 2.5g.At room temperature, the sample that is corroded is placed in the quartzy hanging basket of hollow out, in the etching reagent that with hand control quartzy hanging basket was immersed, proposes above-mentioned preparation in 10 seconds 5 times, this process is 4 minutes continuously.See Fig. 6 dislocation corrosion figure.

Implement 4

The sample that is corroded is substrate Zn _0.04Cd _0.96Te (111) B face.Reagent proportioning: H ₂O: HCl: HNO ₃: K ₂Cr ₂O ₇: CrO ₃=80ml: 8ml: 12ml: 5.1g: 2.5g.At room temperature, the sample that is corroded is placed in the quartzy hanging basket of hollow out, in the etching reagent that with hand control quartzy hanging basket was immersed, proposes above-mentioned preparation in 10 seconds 4 times, this process is 5 minutes continuously.See Fig. 7 dislocation corrosion figure, the corrosion pit type is a triangular.

Implement 5

The sample that is corroded is substrate Zn _0.04Cd _0.96Te (211) B face.Reagent proportioning: H ₂O: HCl: HNO ₃: K ₂Cr ₂O ₇: CrO ₃: HF=80ml: 8ml: 12ml: 5.1g: 2.5g.At room temperature, the sample that is corroded is placed in the quartzy hanging basket of hollow out, in the etching reagent that with hand control quartzy hanging basket was immersed, proposes above-mentioned preparation in 10 seconds 4 times, this process is 5 minutes continuously.See Fig. 8 dislocation corrosion figure, the corrosion pit type is an obtuse angle isoceles triangle type.

Can appear Cd from implementing 4 and 5 etching reagent of the present invention as can be seen _1-yZn _yTe (111) B and (211) face dislocation etch pit.Chen is only to Hg _1-xCd _xThe dislocation corrosion of Te has effect, and it is to Cd _1-yZn _yTe has very strong surface oxidation effect, dislocation etch pit can not occur; Schaake is also only to Hg _1-xCd _xThe dislocation corrosion of Te has effect, to Cd _1-yZn _yTe has corrosive nature, but can not produce corrosion pit.

4 can see sample (111) B face corrosion pit type rule, clearly easily distinguish from implementing, be triangular form.Corrosion pit is divided into triangular and acute angle isoceles triangle type reaches seldom irregular type shape.Wherein triangular is considered to along＜110〉60 ° of perfect dislocations of trend, acute angle isoceles triangle type be＜211〉Schottky (Shockley) of trend screw dislocation entirely; This sample photo does not have irregular type shape corrosion pit, and this irregular corrosion pit is not considered to corresponding with dislocation.

Claims (2)

1. one kind is used for the etching reagent that II-VI family semiconductor material dislocation shows, it is characterized in that:

The proportioning of etching reagent is: H ₂O: HCl: HNO ₃: HF: K ₂Cr ₂O ₇: CrO ₃=80ml: 6-10ml: 10-15ml: 0-5ml: 5.1g: 2.0-7.0g; Said II-VI family semiconductor material is Zn _yCd _1-yThe Hg of Te substrate epitaxial growth _1-xCd _xTe thin-film material and Zn _yCd _1-yTe substrate body material.

2. utilize the caustic solution of the etching reagent that the described a kind of II-VI of being used for of claim 1 family semiconductor material dislocation shows, it is characterized in that step is as follows:

The § A. The pretreatment that is corroded

It is to remove wax and grease in the ebullient trieline that the sample that will be corroded is placed on temperature; Blow the dust and the chip of sample surfaces then with nitrogen gun; Use 0.2%Br-CH at last ₂The OH corrosive fluid corroded for 10 seconds, removed the zone of oxidation of sample surfaces;

§ B. dislocation corrosion

The sample that is corroded is placed in the quartzy hanging basket of hollow out,, repeated this process 2-5 minute in the etching reagent that hanging basket was immersed, propose above-mentioned preparation in 10 seconds with hand control 4-5 time;

The be corroded aftertreatment of sample of § C.

With the deionized water rinsing of the big flow velocity sample that is corroded, the time is greater than 5 minutes, to guarantee the corrosive fluid cleaning down blowing sample surfaces with nitrogen gun then totally with anti-oxidation, dries up up to the water sample surfaces.

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