GB2428885A - Etching solution for identifying defects in silicon - Google Patents
Etching solution for identifying defects in silicon Download PDFInfo
- Publication number
- GB2428885A GB2428885A GB0614880A GB0614880A GB2428885A GB 2428885 A GB2428885 A GB 2428885A GB 0614880 A GB0614880 A GB 0614880A GB 0614880 A GB0614880 A GB 0614880A GB 2428885 A GB2428885 A GB 2428885A
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- defects
- defect
- etching
- solution
- semiconductor material
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Classifications
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/84—Systems specially adapted for particular applications
- G01N21/88—Investigating the presence of flaws or contamination
- G01N21/91—Investigating the presence of flaws or contamination using penetration of dyes, e.g. fluorescent ink
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/84—Systems specially adapted for particular applications
- G01N21/88—Investigating the presence of flaws or contamination
- G01N21/95—Investigating the presence of flaws or contamination characterised by the material or shape of the object to be examined
- G01N21/9501—Semiconductor wafers
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
- H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
- H01L21/04—Manufacture or treatment of semiconductor devices or of parts thereof the devices having at least one potential-jump barrier or surface barrier, e.g. PN junction, depletion layer or carrier concentration layer
- H01L21/18—Manufacture or treatment of semiconductor devices or of parts thereof the devices having at least one potential-jump barrier or surface barrier, e.g. PN junction, depletion layer or carrier concentration layer the devices having semiconductor bodies comprising elements of Group IV of the Periodic System or AIIIBV compounds with or without impurities, e.g. doping materials
- H01L21/30—Treatment of semiconductor bodies using processes or apparatus not provided for in groups H01L21/20 - H01L21/26
- H01L21/302—Treatment of semiconductor bodies using processes or apparatus not provided for in groups H01L21/20 - H01L21/26 to change their surface-physical characteristics or shape, e.g. etching, polishing, cutting
- H01L21/306—Chemical or electrical treatment, e.g. electrolytic etching
- H01L21/30604—Chemical etching
Abstract
The etching solution comprises an oxidizing agent (eg nitric acid), an oxide removal agent (eg hydrofluoric acid) and copper sulphate. The etching occurs preferentially at defect sites (eg stacking faults, bulk micro defects etc) and copper sulphate is preferentially deposited at the defect sites thereby making them visible. A subsequent nitric acid treatment can be used to remove any staining agent deposited at non-defect regions to enhance the visibility of the defects.
Description
1 llethod of identifying the Presence and Severity of 2 Defecte in a
Semiconductor Natarial 4 The present invention relates to a method of identifying the presence, and optionally the 6 severity, of defects in a semiconductor material, 7 and a defect etching solution to preferentially etch 8 defects in a semiconductor material.
Both crystal defects and manufacturing defects occur 11 in semiconductor materials used in the manufacture 12 of devices. The effect of the defect depends on the 13 application of the semiconductor material. For some 14 applications, the presence of defects in devices formed from semiconductor material (such as single 16 crystal silicon wafers) may be beneficial to the 17 manufacture and/or performance of the device. For 18 other applications the presence of defects may be 19 detrimental to the manufacture and/or performance of the device.
1 Crystal defects can arise due to imperfections in 2 the silicon lattice structure or through crystal 3 structure damage o.f the silicon wafer during 4 subsequent processing, such as heat treatment.
Manufacturing defects may arise during the 6 manufacture of devices formed from semiconductor 7 material, in particular during processes such as 8 single crystal silicon ingot cutting and silicon 9 wafer plainerisation processes such as lapping and polishing. Accordingly, the identification and 11 characterisation of crystal defects and 12 manufacturing defects is necessary.
1.4 For some applications it is necessary for the semiconductor material to be defect-free, and for 16 certain applications the presence of defects in a 17 semiconductor material may be beneficial. If one or 18 more defects is present in a location within the 19 wafer that is away from the active device surface of a semiconductor product contaminants in the 21 semiconductor product may be drawn away from the 22 active device surface towards the defect (s).
24 As such, the identification and characterisatIon of defects in semiconductor material is necessary to 26 determine their location and magnitude as this may 27 help determine the quality of the silicon for device 28 manufacture and the application for which the 29 semiconductor material is suitable.
31 Types of crystal defects to which the present 32 invention is applicable include the following: 1 Bulk Micro Defects () 2 Interior defects in silicon are largely induced by 3 oxygen incorporation into silicon and subsequent 4 thermal treatment. The oxygen may be incorporated into the silicon interior during the growth of a 6 silicon crystal or through silicon surface 7 oxidation. The oxygen is usually present throughout 8 the silicon lattice in a discrete manner.
9 Application of certain thermal conditions will help to cause precipitation to form oxygen precipitates 11. or bulk micro defects. The formation of these 12 defects normally requires some sort of nucleation 13 site and will not normally occur due to super- 14 saturation of oxygen within the silicon lattice.
Hence for such defects to form two major factors are 16 normally required prior to any thermal treatment - 17 namely oxygen concentration in the bulk silicon 18 above a certain critical concentration and the 19 presence of nucleation sites. These bulk defects can have two effects on the wafer's potential 21 performance. A very high BMD concentration can 22 result in reduced device yield. A reasonable' 23 concentration of BMD will result in a positive 24 effect for silicon devices as it should create the correct conditions for effective intrinsic 26 gettering. A very low BMD concentration will result 27 in little or no intrinsic gettering which may be 28 detrimental for a silicon based device depending on 29 its application. As a result it is important to be able to measure an approximate concentration of 31 these bulk micro defects within a silicon wafer.
32 This can be achieved by cleave and etch methods 1 using an appropriate selective defect etch, and 2 observation of the etched defect using an optical 3 microscope.
Stacking Faults 6 Stacking faults can be sub-divided into three broad 7 classes. These are Oxidation Induced Stacking Faults 8 (referred to as OS? or OLSF), Bulk Stacking Faults 9 and Epitaxial (or Epi) Stacking Faults.
11 The formation of OiSF is believed to occur as a 12 result of increased numbers of interstitial silicon 13 atoms which nucleate to form the stacking fault.
14 The number of interstitial silicon atoms is primarily influenced by the conditions of growth of the silicon crystal. Thermal treatment in an 17 oxidising atmosphere can generate more silicon 18 interstitials as fewer silicon atoms are used to 19 form silicon dioxide than oxygen atoms. This generates spare silicon atoms during the formation 21 of silicon dioxide using silicon from the crystal 22 and oxygen from the atmosphere. These silicon atoms 23 enter the interstitial sites of the silicon lattice.
24 Generation of the stacking fault is also believed to require a nucleation site. Nucleation sites tend to 26 be strain centres within the silicon bulk and at the 27 surface. The strain centre may be due to, for 28 example, mechanical damage on the surface or an 29 oxygen precipitate within the bulk.
31 Epitaxial stacking faults are found in silicon 32 epitaxial films grown on silicon substrates. This 1 type of stacking fault nucleates at imperfections on 2 the epitaxia]. silicon surface, or in the subsurface 3 region of the silicon substrate and grows into the 4 epitaxial film.
6 Bulk stacking faults can be generated by oxygen 7 precipitation in bulk silicon. Oxygen precipitation 8 is described above and the process will result in 9 excess interstitial silicon in the bulk of the wafer (similar to the situation for OiSF as described 11. above). This can lead to the formation of bulk 12 stacking faults following heat treatment when a 13 certain critical concentration of silicon 14 interstitials has been reached within the silicon lattice.
17 Other Defects 18 Other defect types that can be deliniated by 19 preferential defect etching are discussed below.
21 Swirl defects are found more commonly on float zone 22 grown crystal and less commonly on Czochralski grown 23 crystal. They are usually the result of small 24 dislocation loops formed in a swirl pattern as a result of striations in the crystal during it's 26 growth.
28 Dislocations are generated during crystal growth arid 29 arise as a result of thermal gradients which can occur during the growth process. This results in 31 stresses within the crystal structure due to local 32 expansion and shrinkage due to the non-uniform 1 thermal gradient, which results in a deformation 2 within the lattice resulting in a dislocation.
4 Slip is a plastic deformation in which one part of the crystal undergoes a displacement relative to 6 another but the crystallinity of both parts is 7 maintained.
9 Striations are an apparently helical feature on a wafer surface. These are the result of microscopic 11 compositional inhomogeneities which have arisen 12 during the crystal growth process at the crystal - 13 melt interface due to temperature fluctuations.
Shallow Pits are small etch pits on the silicon 16 surface largely due to small, localised 2.7 contamination impurities. 2.8
19 All of the above defects can be revealed by preferential defect etching solutions. These 21 solutions cause the defect to etch at a different 22 rate to the surrounding silicon as a result of 23 differences in the strength of the crystal in the 24 region of the defect.
26 The identification and characterisation commonly 27 takes the form of a chemical process to highlight 28 the defect or defects in comparison to the 29 surrounding semiconductor material and observe the defects by visual microscope. The defect is 31 highlighted by an etching process (defect etchingu) 32 in which the defect itself is usually etched at a 1 faster rate than the semiconductor material 2 surrounding it. Etches used to do this are 3 described as preferential etches as they etch the 4 defect preferentially in comparison to the surrounding material. Preferential etches generally 6 include an oxidising component and an oxide etch 7 component. The majority of preferential crystal 8 defect etches contain chromium in the +6 oxidation 9 state. Chromium (VI) is a known carcinogen and as such has a severe potential environmental impact and 11 health risk to the user. Efforts have been on-going 12 for over ten years to develop chromium free crystal 13 defect etches. A].]. of these, however, have had only 14 limited use and were only effective for some crystal defects and silicon types. As such, chromium- 16 containing crystal defect etches remain 17 predominantly as the industry standard.
19 Known types of chromium-based etchants include Sirtl, Secco, Wright and Seiter etchants. Known 21 oxidising components include chromium based 22 compounds such as potassium dichroznate and nitric 23 acid.
The oxide etch component of known preferential 26 etches is generally a hydrofluoric acid solution.
28 The etching solution may also incorporate a 29 visibility enhancing agent to enhance the visibility of defects in the semiconductor material making them 31 easier to inspect by optical microscope. Copper 32 nitrate may be used as the visibility enhancing I agent. EP0281115 discloses an etching solution 2 comprising copper nitrate.
4 Copper nitrate selectively etches the etched defects to a greater extent than the surrounding 6 semiconductor material. Rowever, as well as 7 selectively etching the defects, copper nitrate can 8 also stain the surrounding semiconductor material, 9 all be it to a lesser extent and this can result in reduced definition of defects. The staining of the 11 surrounding semiconductor material cannot easily be 12 removed, for instance contact with agents such as 13 nitric acid (which may remove stains on silIcon) 14 does not substantially remove the staining of the surrounding semiconductor material. The difference 16 in staining between the defect and the surrounding 17 material can therefore be slight and semiconductor 18 defects can pass unnoticed. Furthermore there may 19 be poor visible clarity between the defect and the stained surrounding material (such as lack of 21 definition of the etched defects, and lack of 22 sufficient contrast between the etched defect and 23 the surrounding material) such that the severity of 24 the defect is difficult to determine.
26 US 6,174,727 discloses a method of detecting defects 27 on a silicon wafer comprising contacting the silicon 28 wafer with a spiking solution containing copper 29 sulphate. The metal from the spiking solution is deposited on the silicon wafer. There is no 31 teaching or suggestion that the silicon wafer may be 32 etched.
1 The english language abstract of KR9613499 discloses 2 a method of staining semiconductor devices 3 comprising contacting the semiconductor device with 4 a mixture of HF, HN03 and CH3COOM. The semiconductor device is then solved by contacting the 6 semiconductor device with copper sulphate. There is 7 no teaching or suggestion that the silicon wafer may 8 be etched.
According to a first aspect of the present invention 11 there is provided a method of identifying the 12 presence of defects in a semiconductor material 13 comprising the steps of etching at least one surface 14 of the semiconductor material using a defect etching solution wherein the defect etching solution 16 comprises a visibility enhancing agent comprising 17 copper sulphate to increase the selectivity of the 18 defect etching solution to defects in the 19 semiconductor material relative to areas of the semiconductor material without defects. 2].
22 As such any defect in the semiconductor material is 23 etched far more by the method of the present 24 invention than surrounding areas of semiconductor material without defects. The greater the severity 26 of the defect, the greater the extent of the etching 27 from the method of the present invention.
29 The presence and severity of any defects in the semiconductor material can easily be assessed 31. following etching of the semiconductor material by 32 the method of the present invention.
1 Advantageously, the visibility enhancing agent 2 increases the selectivity of the defect etching 3 solution to defects relative to surrounding material 4 to a greater extent than known visibility enhancing agent, such as copper nitrate. The extent of 6 etching at defects relative to surrounding material 7 is greater using the method of the present invention 8 compared to the extent of etching associated with a 9 defect etching method which employs known visibility agents, such as copper nitrate.
12 Suitably, the presence of the visibility enhancing 13 agent comprising copper sulphate enhances the 14 visibility of defects in the semiconductor material.
16 The method of the present invention selectively 17 etches the defect. The method of the present 18 invention may also cause some staining of the 19 material surrounding the defect. However, in contrast to known etching methods any staining of 21 the surrounding material can be partially or fully 22 removed by stain removal agents such as nitric acid.
23 The contrast between the etched crystal defect and 24 the surrounding material is therefore greater for semiconductor material subjected to the method of 26 the present invention than for semiconductor 2? material subjected to known etching methods such as 28 those that employ known visibility enhancing agents, 29 such as copper nitrate. The definition of the crystal defect compared to any staining of the 31 surrounding material is good relative to known 32 visibility enhancing agents such as copper nitrate. 11.
1 Identification and characterisation of the defects 2 is therefore simpler and more accurate than for 3 previously known methods.
According to one aspect of the present invention the 6 staining of defects is significantly darker than 7 staining of the surrounding semiconductor material.
8 This is believed to be because the defects are 9 etched far more than the surrounding material and because the copper sulphate visibility enhancing 1]. agent causes the defect to be etched to a far 12 greater extent than the surrounding material.
13 Semiconductor defects etched according to the method 14 of the present invention appear darker than semiconductor defects stained using known defect 16 etch solutions such as those comprising known 17 stainIng agents, for example copper nitrate.
19 A subjective judgement, similar to those detailed in the ASTM Standards (Designation F 1809 relating to 21 etching solutions to deliniate structural defects in 22 silicon) may classify the staining of the defects by 23 the method of the present invention as A = 24 excellent'. In comparison, a similar judgement may classify defects etched using known defect etch 26 solutions such as those comprising known staining 27 agents, for example copper nitrate as B good'.
29 The method of the present invention provides contacting the semiconductor material with the 31 defect etching solution and the visibility enhancing 1 agent simultaneously as the defect etching solution 2 comprises the visibility enhancing agent.
4 If the semiconductor material is contacted with the S visibility enhancing agent prior to contact with the 6 defect etching solution, a layer of copper sulphate 7 may be deposited on the semiconductor material, and 8 the defect etching solution would etch the copper 9 sulphate layer rather than the semiconductor material itself. As such, any defects in the 11 semiconductor material would not be etched to the 12 same extent as they would be in accordance with the 13 method of the present invention. The presence and 14 severity of semiconductor defects would be difficult or impossible to assess.
17 If the semiconductor material was contacted with the 18 visibility enhancing agent following contact with 19 the defect etching solution the selectivity of the etching solution to defects in the semiconductor 21 material would not be increased, and the visibility 22 of defects present on the semiconductor material 23 would not be enhanced.
Suitably the semiconductor material used in the 26 method of the present invention is silicon.
27 Preferably the semiconductor material is formed from 28 silicon wafer.
The defects identified by the method of the present 31 invention may be manufacturing defects or crystal 32 defects such as bulk micro defects (BMD), stacking 1. faults, swirl defects, dislocations, slip, 2 striations or shallow pits.
4 The defect etching solution suitably includes an oxidising component, an oxide etching component and 6 the visibility enhancing agent.
8 The oxide etching component is suitably a chromium 9 (VI) -based etchant or a manganese (VII) -based etchant. Accordingly, the defect etching solution 11 of the present invention may suitably be chromium- 12 free, thus avoiding the environmental effects, and 13 health risks of known chromium-containing crystal 14 defect etches.
16 The oxidising component of the defect etching 17 solution of the present invention may comprise a 18 perinanganate compound, preferably potassium 19 permanganate. The oxidising component is suitably hydrogen fluoride or a solution of hydrofluoric 21 acid.
23 In one embodiment of the method of the present 24 invention all surfaces of the semiconductor material are etched using the defect etching solution.
27 Suitably the surface or surfaces of the 28 semiconductor material are contacted with the defect 29 etching solution for a period in the range of 0.2 to 4 minutes, or sufficient to remove about 1 to 12 pin 31 of silicon.
1 Following etching, the semiconductor material is 2 suitably contacted with a stain removal agent. The 3 stain removal agent may remove the stain from the 4 surrounding semiconductor material whilst maintaining the contrasting appearance of the 6 defects.
8 The stain removal agent is suitably an acid solution 9 such as a nitric acid solution. Preferably the stain removal agent is a 10 wt/wt% nitric acid 11 solution.
13 After the semiconductor material has been contacted 14 with the defect etching solution, and suitably after the visibility of the defects has been enhanced, the 16 semiconductor material is suitably visually 17 inspected to identify the presence of defects, for 18 instance through direct visual inspection or by 19 means of an optical microscope.
21 In one embodiment of the present invention the 22 defects identified are characterised according to 23 their severity.
The method may include the step of assessing the 26 application for which the semiconductor material is 27 suitable by assessing the number of defects present 28 in the semiconductor material and the severity of 29 the defects identified.
31 According to a further aspect of the present 32 invention there is provided a defect etching 1 solution comprising a visibility enhancing agent 2 wherein the visibility enhancing agent comprises 3 copper sulphate.
Suitably the visibility enhancing agent increases 6 the selectivity of the etching solution to defects 7 in the semiconductor material relative to areas of 8 the semiconductor material without defects.
Typically the visibility enhancing agent causes the 11 defects in the semiconductor material to become more 12 etched than surrounding semiconductor material, thus 13 enhancing the visibility of the defects.
Suitably any staining of the surrounding 16 semiconductor material may be fully or partially 17 removed by contact with a stain removal agent. 3.8
19 Advantageously, the visibility enhancing agent comprises copper (II) sulphate. 21.
22 In one embodiment of the present invention the 23 defect etching solution includes an oxidising 24 component and an oxide etching component for preferentially etching defects in the semiconductor 26 material.
28 The oxidising component may be chromium-based, 29 suitably chromium (VI) based. Alternatively the oxidising component may be manganese (VII) based or 31 nitric acid. Suitably the oxidising component is 32 potassium permanganate.
1 The oxide etching component is suitably hydrogen 2 fluoride or species which form hydrogen fluoride in 3 situ. The oxide etching component may be a 4 hydrofluoric acid solution.
6 In particularly preferred embodiments, the oxidising 7 component comprises a potassium permanganate 8 solution with a molar concentration in the range 9 0.05 to 0.3, the oxide etching component comprises a solution of hydrofluoric acid with a concentration 1]. of 48% (+1-2%) by weight, and the visibility 12 enhancing agent comprises a copper sulphate solution 13 with a molar concentration of 0.1 to 0.3.
Preferably, the defect etching solution comprises 16 the oxidising component and the oxide etching 17 component in the ratio 1:2 or the oxidising 18 component, the oxide etching component and the 19 visibility enhancing component in the ratio 4:8:1 or 4:4:1.
22 In one embodiment of the present invention the 23 defect etching solution comprises potassium 24 permanganate, HF and copper sulphate in a ratio of 4:8:1.
27 Alternatively the defect etching solution comprises 28 a chromium (Vt) based compound as the oxIdising 29 component, a hydrofluoric acid solution as the oxide etching component and copper sulphate as the 31 visibility enhancing agent in a ratio of 4:8:1.
1 According to a further aspect of the present 2 invention there is provided the use of the defect 3 etching solution described above for identifying arid 4 characterising defects in a semiconductor material.
6 The present invention will now be described by way 7 of example only with reference to the accompanying 8 Figures in which; Figure 1 shows an image at x500 magnification of a ii. wafer section following immersion in known defect 12 etching solution (a) of Example 1 and immersion in a 13 10 wt/wt% nitric acid stain removal solution; Figure 2 shows the image of Figure 3. at a lower 16 magnification; 18 Figure 3 shows an image at x500 magnification of a 19 wafer section following immersion in defect etching solution (b) of the present invention; 21.
22 Figure 4 shows an image at x500 magnification of a 23 wafer section following immersion in defect etching 24 solution (b) of the present invention and immersion in a 10 wt/wt% nitric acid stain removal solution; 27 Figure 5 shows the image of Figure 3 at a lower 28 magnification; Figure 6 shows an image of a wafer section following 31 immersion in defect etching solution (b) of the 1 present invention and immersion in a 10 wt/wt% 2 nitric acid stain removal solution.
4 Eacap1o 1 A sample of polished silicon wafer was oxidized in 6 order to encourage the growth of any oxidation 7 induced stacking faults that might be present. The 8 sample of polished silicon wafer had the following
9 specification.
U Wafer diameter = 200mm 12 Oxygen content = 6.25 x 10"ppma (by ASTM F-121-80) 13 Resistivity = 0.0065 ohzn.cxn 14 Crystal orientation = <1-0-0> Dopant = p-type boron 17 The silicon wafer was cleaved along crystallographic 18 planes into smaller sections to allow evaluation of 19 the same sample in different etch solutions and under different conditions. The wafer sections were 21 then immersed in crystal defect etching solutions as 22 described below: 24 Defect etching solutions: 26 (a) 0.175M KMnO4; 48% HF; 0.1414 Cu(IX)N03 in a 27 ratio of 4:8:1; 28 (b)0.175M K14n04; 48% HF; 0.14M Cu(II)S04 in a ratio 29 of 4:8:1.
31 It may be noted that defect etching solution (b) is 32 of the present invention.
1 A wafer section was immersed for 120 seconds in 2 etching solution (a) and the wafer section was 3 agitated during this period. Following immersion 4 the wafer section was rinsed to remove the etching solution and allowed to dry before inspection. In 6 an attempt to remove staining from the wafer surface 7 the sections were immersed in a solution of nitric 8 acid (concentration approx. 10 wt/wt%) before final 9 rinsing and drying. The experiment was then repeated using etching solution (b).
12 The defects of wafer sections contacted with defect 13 etching solution (b) of the present invention are 14 identified far more clearly than defects of wafer sections contacted with known defect etching 16 solution ( a). There is high contrast between the 17 defects of wafer sections contacted with defect 18 etching solution (b) and the surrounding silicon 19 wafer, particularly after the wafer has been dipped in the stain removal agent (see Figures 3, 4 and 5).
21 In contrast, for the wafer sections contacted with 22 defect etching solution (a) there is less 23 distinction between the appearance of the defects 24 and the staining of the surrounding silicon wafer (see Figures 1 and 2). The defects etched by 26 etching solution (b) appear larger and have more 27 definition at the same optical microscope 28 magnification than those etched by etching solution 29 (a). There is more contrast between the defects etched by etching solution (b) and the surrounding 31 material than defects etched by etching solution 32 (a).
1. All documents referred to in this specification are 2 hereby incorporated by reference. Various 3 modifications and variations to the described 4 embodiments of the invention will be apparent to those skilled in the art without departing from the 6 scope and spirit of the invention. Although the 7 invention has been described in connection with 8 specific preferred embodiments, it should be 9 understood that the invention as claimed should not be unduly limited to such specific embodiments.
11 Indeed, various modifications of the described modes 12 of carrying out the invention which are obvious to 13 those skilled in the art are intended to be covered 14 by the present invention.
Claims (1)
1 Claims 3 1. A method of identifying the presence of 4 defects in a
semiconductor material comprising etching at least one surface of the 6 semiconductor material using a defect etching 7 solution wherein the defect etching solution 8 comprises a visibility enhancing agent 9 comprising copper sulphate to increase the selectivity of the defect etching solution to 11 defects in the semiconductor material relative 12 to the surrounding semiconductor material.
14 2. The method of Claim 2. wherein the extent of the etching increases with the severity of the 16 defect.
18 3. The method of either one of Claims 1 and 2 19 wherein defects are etched more than the surrounding semiconductor material thus 21 enhancing the visibility of defects in the 22 semiconductor material.
24 4. The method of any preceding claim wherein the extent of the etching increases with the 26 severity of the defect.
28 5. The method of any preceding claim wherein the 29 defects identified are manufacturing defects or crystal defects.
1 6. The method of any preceding claim comprising 2 the step of contacting the semiconductor 3 material with a stain removal agent subsequent 4 to contacting the semiconductor material with the defect etching solution wherein the stain 6 removal agent acts to remove staining from the 7 semiconductor material surrounding the defects 8 whilst substantially maintaining the 9 appearance of the defects.
11 7. A defect etching solution for preferentially 12 etching defects in a semiconductor material, 13 comprising a visibility enhancing agent 14 wherein the visibility enhancing agent comprises copper sulphate.
17 8. The defect etching solution of Claim 7 wherein 18 the visibility enhancing agent comprises 19 copper (II) sulphate.
2]. 9. The defect etching solution of either one of 22 Claims 7 and 8 comprising an oxidising 23 component and an oxide etching component.
10. The defect etching solution of Claim 9 wherein 26 the oxidising component is chromium (VI) 27 based, manganese (VII) based or nitric acid.
29 11. The defect etching solution of either one of Claims 9 and 10 wherein the oxide etching 31 component is hydrogen fluoride or hydrofluoric 32 acid solution.
1 12. The defect etching solution of any one of 2 Claims 9 to 1]. wherein the oxidising component 3 comprises a solution of potassium permanganate 4 with a molar concentration in the range 0.05 to 0.3, the oxide etching component comprises 6 a solution of hydrofluoric acid with a 7 concentration of 48% (+1-2%) by weight and the 8 visibility enhancing agent comprises a copper 9 sulphate solution with a molar concentration of 0.]. to 0.3.
12 13. The defect etching solution of any one of 13 Claims 9 to 12 comprising the oxidising 14 component, the oxide etching component and the visibility enhancing component in a ratio in 16 the range of 4:4:]. to 4:12:1.
18 14. The defect etching solution of any one of 19 Claims 9 to 11 wherein the oxidising component comprises a solution of potassium 2]. permanganate, the oxide etching component 22 comprises HF and the visibility enhancing 23 component comprises copper sulphate in a ratio 24 in the range of 4:4:1 to 4:12:1.
26 15. The use of the defect etching solution of any 27 one of Claims 7 to 14 for identifying and 28 characterising defects in a semiconductor 29 material.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB0515480A GB0515480D0 (en) | 2005-07-28 | 2005-07-28 | Product |
Publications (3)
| Publication Number | Publication Date |
|---|---|
| GB0614880D0 GB0614880D0 (en) | 2006-09-06 |
| GB2428885A true GB2428885A (en) | 2007-02-07 |
| GB2428885B GB2428885B (en) | 2010-07-28 |
Family
ID=34976739
Family Applications (3)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB0515480A Ceased GB0515480D0 (en) | 2005-07-28 | 2005-07-28 | Product |
| GB0614202A Ceased GB0614202D0 (en) | 2005-07-28 | 2006-07-18 | Method of identifying the presence and severity of defects in a semiconductor material |
| GB0614880A Active GB2428885B (en) | 2005-07-28 | 2006-07-27 | Method of identifying the presence and severity of defects In a semiconductor material |
Family Applications Before (2)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB0515480A Ceased GB0515480D0 (en) | 2005-07-28 | 2005-07-28 | Product |
| GB0614202A Ceased GB0614202D0 (en) | 2005-07-28 | 2006-07-18 | Method of identifying the presence and severity of defects in a semiconductor material |
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| Country | Link |
|---|---|
| GB (3) | GB0515480D0 (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP2226374A1 (en) * | 2009-03-06 | 2010-09-08 | S.O.I. TEC Silicon | Etching composition, in particular for silicon materials, method for characterizing defects of such materials and process of treating such surfaces with etching composition |
| WO2015150156A1 (en) * | 2014-04-01 | 2015-10-08 | Atotech Deutschland Gmbh | Composition and process for metallizing nonconductive plastic surfaces |
| WO2021243447A1 (en) * | 2020-06-02 | 2021-12-09 | Techinsights Inc. | Contrast-enhancing staining system and method and imaging methods and systems related thereto |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0281115A2 (en) * | 1987-03-04 | 1988-09-07 | Kabushiki Kaisha Toshiba | Etching solution for evaluating crystal faults |
| KR960013499B1 (en) * | 1988-04-30 | 1996-10-05 | 엘지반도체 주식회사 | Staining method for vertical structure monitoring of semiconductor device |
-
2005
- 2005-07-28 GB GB0515480A patent/GB0515480D0/en not_active Ceased
-
2006
- 2006-07-18 GB GB0614202A patent/GB0614202D0/en not_active Ceased
- 2006-07-27 GB GB0614880A patent/GB2428885B/en active Active
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0281115A2 (en) * | 1987-03-04 | 1988-09-07 | Kabushiki Kaisha Toshiba | Etching solution for evaluating crystal faults |
| KR960013499B1 (en) * | 1988-04-30 | 1996-10-05 | 엘지반도체 주식회사 | Staining method for vertical structure monitoring of semiconductor device |
Cited By (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP2226374A1 (en) * | 2009-03-06 | 2010-09-08 | S.O.I. TEC Silicon | Etching composition, in particular for silicon materials, method for characterizing defects of such materials and process of treating such surfaces with etching composition |
| WO2010099982A1 (en) * | 2009-03-06 | 2010-09-10 | S.O.I. Tec Silicon On Insulator Technologies | Etching composition, in particular for silicon materials, method for characterizing defects on surfaces of such materials and process of treating such surfaces with the etching composition |
| WO2015150156A1 (en) * | 2014-04-01 | 2015-10-08 | Atotech Deutschland Gmbh | Composition and process for metallizing nonconductive plastic surfaces |
| CN106471155A (en) * | 2014-04-01 | 2017-03-01 | 安美特德国有限公司 | For making compositionss and the method for nonconductive plastic material surface metalation |
| JP2017517626A (en) * | 2014-04-01 | 2017-06-29 | アトテツク・ドイチユラント・ゲゼルシヤフト・ミツト・ベシユレンクテル・ハフツングＡｔｏｔｅｃｈ Ｄｅｕｔｓｃｈｌａｎｄ ＧｍｂＨ | Compositions and methods for metallizing non-conductive plastic surfaces |
| US10174250B2 (en) | 2014-04-01 | 2019-01-08 | Atotech Deutschland Gmbh | Composition and process for metallizing nonconductive plastic surfaces |
| US10377947B2 (en) | 2014-04-01 | 2019-08-13 | Atotech Deutschland Gmbh | Composition and process for metallizing nonconductive plastic surfaces |
| CN106471155B (en) * | 2014-04-01 | 2019-11-15 | 安美特德国有限公司 | For making the composition and method of nonconductive plastic material surface metalation |
| EP3660189A1 (en) * | 2014-04-01 | 2020-06-03 | ATOTECH Deutschland GmbH | Composition and process for metallizing nonconductive plastic surfaces |
| WO2021243447A1 (en) * | 2020-06-02 | 2021-12-09 | Techinsights Inc. | Contrast-enhancing staining system and method and imaging methods and systems related thereto |
Also Published As
| Publication number | Publication date |
|---|---|
| GB0614880D0 (en) | 2006-09-06 |
| GB2428885B (en) | 2010-07-28 |
| GB0515480D0 (en) | 2005-08-31 |
| GB0614202D0 (en) | 2006-08-23 |
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