NIST2000SRM - XRR Data! Excitingly close match to that theoretically simulated by Bruker LEPTOS. Wait till you get an eye full of this data:-)

"This Standard Reference Material (SRM) provides the high-resolution X-ray diffraction (HRXRD) community with International System of Units (SI) [1] traceable Si (220) d-spacing in transmission, surface-to-crystal-plane wafer miscut, and surface-to-Si (004) Bragg angle in reflection for our reference wavelength. A unit of SRM 2000 consists of 25 mm × 25 mm × 0.725 mm double-polished (100)-oriented, single-crystal Si specimens with a nominal 50 nm Si0.85Ge0.15 epitaxial layer and 25 nm Si cap."

So, our values of 49.92nm (0.16% deviation) for SiGe and 26.02nm (4+% deviation) for Si cap layer are reasonable based on our XRR data. What do you think? NDE & Real Time!

The XRR data was acquired using the Omega-2Theta coupled rocking curve scan :-)

Nomenclature used for the term XRD "rocking curve":

Two simple distinctions are recognized.

Feedback of the XRD community conventions and norms for the usage of these terms would be helpful in being unequivocal when communicating.

https://www.researchgate.net/post/Would_anyone_have_a_clue_as_to_the_origin_of_unexpected_spots_in_the_real_time_2D_XRR_signal_from_thin_film_samples_on_substrates_Yuneda_Spots

Relative Reciprocal Space Images! Brand new full video of all the awesome reciprocal space analyses coming up soon. Stay tuned!

The leading edge in XRD!

Here are 5 versions of the video summary presentation for the data we collected. Please review and provide your invaluable feedback whenever convenient. Thanks a million!

A. No Audio: https://www.youtube.com/watch?v=cPHxaHP8dMg

B. HipHop: https://www.youtube.com/edit?o=U&video_id=81RmuZ3ilNA

C. Electric: https://www.youtube.com/watch?v=-hkQVpAmcCY

D. Eastern: https://www.youtube.com/watch?v=UOBxgtDXG-s

E. Rock: https://www.youtube.com/watch?v=D-bwgAVkM5I

What is your order of preference among these videos (A through E)? Vote! I mean music:-)

https://www.youtube.com/watch?v=-hkQVpAmcCY

Micro-topo-tomographic observations in crystalline materials! the extinction depth for this LaAlO-Nd2NiO4 sample was estimated at 13.2um using Cu K Alpha 1.

The sample was supposedly a 20nm thin film of NNO(Nd2NiO4) on a LAO (LaAlO) "monocrystalline" substrate. We were observing the (013) asymmetric reflection's rocking curve profiles. The image attached is a series of RCP's for a single vertical cursor line, at about the center of the XRD topograph, displayed in pseudocolor to show the relative intensities. Pixel size is 29 um spatially. The Omega map has a resolution of roughly 0.75 Arcsec per pixel.

The pseudocolor spots and corresponding topographs indicate the ability (https://www.flickr.com/photos/85210325@N04/16316521660/ ) to isolate overlapping coherently diffracting domains (CDD's) for individual VOXELS/Pixels on the topograph (sample surface) in the 3D reciprocal space (X, Y, Omega) of relative intensity values.

PS - Relative Bragg Peak Position Map

FWHM - Relative Bragg FWHM Map

II - Relative Integrated Intensity Map

Is it possible to identify the depth in each VOXEL from which each fully resolved "spot" of the CDD in the 3D reciprocal space originates?

The reason I'm airing this out in this forum is that I know from the member profiles that many of you are already familiar with the advantages of the XRD rocking curve method for quantifying minute Nanostructural details. Mostly, using the conventional approach with a 0D point source and a 0D "point" detector. Even those of you that have a 1D or 2D detector, are predominantly using those in the 0D-Mode for XRD rocking curve analyses. Once you extract yourself from the veil of "conventionality" it is a whole "Brave New World"! I believe I'm surfing on the leading edge of technology. Wonder if anyone else in this audience is? I see no publications yet in the literature. Join me and share! We sure could use a bit of your help with critical examination, both constructive or otherwise :-)

One clear fact, based on many unabashed remarks of several of this group's members, is that, there is no lack of temerity to point out errors and bogus information. Besides there certainly is NO LACK OF EXPERTISE in our membership! So, go for it!

Relevant links and information would help us all out simultaneously.

For instance, in order to duplicate this data using the conventional method one would have to do the following:

(1). Reduce the point source of the parallel incident beam to roughly 29umX29um size.

(2). Invest 2-30 minutes for each RCP (rocking curve profile) depending on the sensitivity of the detector as a result of the dramatically lower signal strength.

(3). Then come up with 816x816=640,000+ rocking curve profiles by rastering the sample surface 640,000+ times, each RCP with 2000 data points. At 2 min. each RCP, that would amount to 900+ days 7/24/366:-) No hardware or sample translation mechanism would last that torture without all kinds of "backlash" errors just due to wear & tear.

Majority of the expertise in this area is still among the Synchrotron users. Others do not have sufficient SNR (Signal to Noise Ratio) from Laboratory sources. We have the "equalizer"! Come see! :-)

https://www.flickr.com/photos/85210325@N04/16316521660/

The image above is a planer cross section in reciprocal space (x,y,Omega) along a x/y cursor line on the 2D topograph. Prior to the XRD rocking curve observations we optimized the reflection so that one of the family of directions was parallel to the rocking axis or diffractometer axis (z-axis) as well. The Omega maps clearly show identifiable coherrent diffracting domains (CDD) and we have shown the "section" topograph of each CDD circled in the "Omega Map". The penetration depth was estimated at 13.2um into the sample for the geometry/optics used.

https://www.flickr.com/photos/85210325@N04/16316521660/

Latest Reciprocal Space Images in several renderings and perspectives:

This time we got the (113) reflection and the 3D RSI (Reciprocal Space Image) for the NIST2000SRM sample. I can't wait to visualize the data soon :-)

This standard sample is a "Pandora's Box" for XRD rocking curve analyses and Reciprocal Space Imaging. Typical data sets are easily in the 30GB range. We are trying to enlarge this limitation constantly. Having fun doing so!

NIST2000SRM! Behold, (113) Asymmetric Reflection Topography (ART?)!

• Figure 1, Collage: https://www.flickr.com/photos/85210325@N04/16430007534/
• Figure 2, RCP & 3D: https://www.flickr.com/photos/85210325@N04/17051620761/

Real time frame rate was about 13fps which in this case of (113) was equivalent to 0.1154 Arcsec per frame Omega resolution. All rocking curves were Omega only de-coupled with the 2D detector fixed at 2-Theta Bragg. The SDD, sample to detector distance, was 65mm for these observations. At this sample to detector distance the 25mm detector input window creates an acceptance angle of roughly 14 degrees 2-Theta and a 27-28 um pixel subtends an angle of 89 Arcsec at the rocking axis (sample surface) . Due to the geometry used, 56.12 degrees 2-Theta Bragg and Omega of 2.55 to 2.65 degrees the the "Pixel" on the sample surface is a bit distorted. Dimensions are displayed in the summary collage image below and in Figure 1 above.

SDD 100mm; Angular velocity for rocking curve was 0.025o per min.=0.1154 Arcsec per frame @ 13fps; Effective pixel size on the sample surface would be about 35um(H) x 27um(V) for the (113) reflection geometry.

• Figure A - Relative Integrated Intensity (II) Map NIST2000SRM (113) ACT https://www.flickr.com/photos/85210325@N04/16866215489/
• Figure B - Relative Bragg Peak Shift (PS) Map NIST2000SRM (113) https://www.flickr.com/photos/85210325@N04/16864657238/
• Figure C - Relative FWHM Map NIST2000SRM (113) ACT https://www.flickr.com/photos/85210325@N04/16845026647/in/photostream/

Relative Bragg Peak Shift range is about 29 Arcsec while the FWHM ranges from 7-29 Arcsec for the (113) asymmetric reflection.

Computing equatorial beam divergence for the Bruker D8 optics!

NIST2000SRM (113) asymmetric reflection FWHM Map https://www.flickr.com/photos/85210325@N04/17074555662/

https://www.flickr.com/photos/85210325@N04/17074555662/

Figure A - Relative Integrated Intensity (II) Map NIST2000SRM (113) ACT https://www.flickr.com/photos/85210325@N04/16866215489/

The observation of vertical striations on the real time topograph and its XRD rocking curve Integrated Intensity (II) Map is unique to this sample, reflection (ACT - asymmetric crystal topography) and incident beam optics. Since it is so predominant in the Integrated Intensity Map, I tend to think it may be system generated. I'd have to demonstrate it by reproducing a similar topograph and reciprocal space image from a different specimen with identical apparatus. I remain open minded :-)

I also intend to look at the incident beam emanating from the Bruker D8 (https://www.flickr.com/photos/85210325@N04/16877294340/) beam conditioner [Gobel+Ge (220)] at a higher spatial resolution by tilting the detector plane w.r.t. the incident beam (position # 3 in the figure https://www.flickr.com/photos/85210325@N04/9311681113/in/set-72157632724094863), while maintaining the beam at the center of the detector surface) in order to spread the beam over a larger 2D area. This would also reduce the flux and any associated saturation effects. Kind of sort of like "Asymmetric Detector Topography"? I'd see the evidence immediately, if the culprit was beam conditioner :-)

https://www.flickr.com/photos/85210325@N04/16877294340/

https://www.flickr.com/photos/85210325@N04/9311681113/in/set-72157632724094863

Quantifying image shift with changing SDD 65mm & 100mm.

Comparing (113) & (224) for NIST2000SRM

The only common feature between these two reflections is the similarity in the relative Bragg integrated intensity maps. These striations appear to be coming from the system rather than sample Nano structure, in my opinion so far. One experiment to conclusively establish the origin of these striations, is by laterally displacing the specimen and repeating the XRD rocking curve topograph. If the striations move then their origin is most likely from the sample surface, if not then most likely culprit would be the incident beam conditioning optics :-)

Si wafer with IC's (224) ACT! 

Intensity striations are seen in the real time topograph and the rocking curve Integrated Intensity Map. The IC's are visible as well :-) We'll need more data to improve certitude of conclusions. But the striations are more likely system generated. 

NIST2000SRM (224) ACT

0.75 Arcsec per video frame. 0.25 degree per min angular velocity for Omega only decoupled XRD rocking curve measurements.

ROCKING CURVE TOPOGRAPHY(113) NIST 2000 SRM

Evidence of sub-grain structure. State-of-the-art!

The Leading Edge of Technology!

DPM- Degree per minute scan rate;

FPS/fps- Frames per second, 2D XRD data acquisition rate. 816x816 Pixels per frame!

Interesting statistics in 5 months after this post! 

No likes/dislikes! 6 followers with no comments! 325 views, mostly probably mine :-)

No one has even a question about the technique in this erudite audience? Amazing! I thought otherwise all along. Bummer :-(

I have patience! It's only been 3 decades since we initially published this advantage. I'll wait it out till minds open :-)

We intend to compare our 2D detector results with the conventional 0D detector and the more advanced 1D detector as well. We also intend to demonstrate real time RSM capabilities for each 27um Pixel (800X800) on the topograph. That gets me excited!

Since you are watching (some of you), let me stick my neck out even further.

Here, I believe, is a NDE map of the lattice "strain field" due to relative dislocation density (FWHM2) as seen on the (113) plane for the NIST 2000 SRM in simple grey (B/W) and no fancy pseudo-color. Now, can anyone of you XRD "experts" tell us if this image could be from anything other than the sample Nano structure? 

Dislocation Density, ρ=β2/9b2 for a Gaussian distribution, b=Burgers Vector, ρ-Dislocation Density, integral breadth, β, is related to the FWHM peak width, H, by β = 0.5 H (π / loge2)1/2

If someone can find translations & additional articles for dislocation theory and post them, that would be a great advantage to all of us in the XRD community.

Attached is a monograph from Jans Burgers in 1980. In it he refers to a blurb on dislocation theory in Nature 1935.

He introduced screw dislocations in 1939 but the journal is inaccessible (ref below) BURGERS, J. M., Proc. Acad. Sci., Amsterdam, 42, 293 (1939); 42, 378 (1939).

Burgers theory was completed in another inaccessible book called:

Plastische Eigenschaften von Kristallen und metallischen Werkstoffen Volume 7 1941. Authors:Dr. habil. Albert Kochendörfer, ISBN: 978-3-642-98485-3 (Print) 978-3-642-99299-5 (Online),

http://link.springer.com/book/ 10.1007%2F978-3-642-99299-5

I'm attaching all these documents so that I may find them easily. RG is a convenient info source!

NIST 2000 SRM (113) Asymmetric Reflection Topography (ACT) using Bruker D8 diffractometer system!

WIP! The attached figure displays the (113) topograph for the NIST 2000 SRM along with three 63x63 Pixels RoI (region of interest) i.e., 2000 Pixels (RCP's) or 1.732x1.732 mm2. It is interesting to observe the near congruence with the GaAs (004) theoretical RCP on the lower angle side of the Bragg peak while a systematic shift is evident on the higher angle side. Each RCP was normalized w.r.t. the total integrated intensity under it. I'm yet to understand the "root cause" of the systematic shifts. RCP #2 in "aqua blue", is a near identical fit with the theoretical GaAs (004) profile ("white") below it generated by Bruker LEPTOS S/W. Any suggestions?

What are the potential causes for the asymmetric distortion of the Bragg Peak in terms of the material's Nano structure?

Note: I'm using the LEPTOS generated GaAs (004) RCP only because that is all I have. I'll have the correct LEPTOS generated theoretical profile for the NIST2000SRM soon to share with you :-)

Testing video data upload? Forget the technical advantage for now! What do you think of the music in the YouTube videos. This is a blatant attempt to promote this awesome Bob Marley music :-) check it out! JAAMMMING MAAN! (.wmv video file attached)

A comparison of the NIST 2000 SRM (113) RCP (rocking curve profile) with that of the simulated strain free substrate Bragg profile for (004) GaAs generated by Bruker LEPTOS software! "If the glove doesn't fit then you must acquit"! "If the profile fits then you mustn't resist"? https://www.flickr.com/photos/85210325@N04/17266501542/in/dateposted-public/

Quantifying & imaging deviations from IDEAL BRAGG PROFILE: https://www.flickr.com/photos/85210325@N04/17115049969/in/dateposted-public/

https://www.youtube.com/watch?v=tPExZM1hxz0

https://www.youtube.com/watch?v=KmrtGvZRCaE

https://www.youtube.com/watch?v=ftZJYQcsZAY

Here is data from the "back side" (rear end, flip side) of the NIST 2000 SRM  :-)

For those in the "know", you'd want this capability in your XRD lab by now at least unless you are completely clueless. The data is self explanatory. It is the asymmetric "(113)-" (grazing incidence angle) reflection with identical optics as before but on the reverse side of the sample with the ID numbers (1 08 42) inscribed on it. Check out the contrast from the electrically scribed letters in the FWHM (relative "excess" dislocation density) map! The XRD RCP's (rocking curve profile) FWHM map shows the variations in the relative defect density. Ideally we should be mapping FWHM2 instead of just the FWHM:

• on the letters,
• inside the letters, and
• far away from the letters

The "skewness" is about 15 degrees South!

https://www.flickr.com/photos/85210325@N04/17491023638/in/datetaken/

https://www.flickr.com/photos/85210325@N04/17968063325/in/dateposted-public/

Behold! 75mm wafer of SiC 6H (109)- grazing incidence reflection topography!

Expected values for SiC 6H (109)- are:

• 2Theta=65.3473o (actual 65.749o)
• Omega=0.5097o (actual 0.456722o)

DPM (degree per minute)=0.06o-0.12o, SDD (sample-to-detector-distance)=59mm, 0.2mm slit, 27.5um per Pixel, 12.5fps, 40kV, 40mA, Cu KAlpha 1

Images included below are:

Here is the main beam after rigorous alignment procedure using the Bruker Lynxeye detector lasting nearly a whole day by a "super-expert" level operator.

Ever got this close to the main beam and stared it in the eye with any other 2D detector? Do you realize how critical this examination of the incident beam profile & shape factor is for subsequent XRD analyses?

Excel summary NIST 2000 SRM

The data I've analyzed thus far from the NIST 2000 SRM has emboldened me significantly regarding the use of 2D topographic techniques in XRD rocking curve analyses. I do have a renewed respect for the conventional 0D technique and its proponents as well after personally using the method for the first time in the recent months. However, the advantages of the 2D XRD Rocking Curve methodology has become abundantly clear to me. I continue to remain open-minded to constructive criticism. Be prepared for a rebuttal though :-)

In the interest of "full disclosure" here is a data comparison between using "slit" and without "slit":

SiC 6H (109)- with slit first!

Abbreviations used:

SiC 6H (109)- without slit next! OPEN BEAM as is from the source through the beam conditioners (Curved Mirror Plus Channel Cut  Monchromator) yielding "pure" Kalpha1! Not really "pure" but with the "instrumental profile" convoluted :-)

Tough to tell the difference. Please download, review and comment if possible.

The leading edge of technology!

Thanks Klaus! Materials Oscilloscope is a whole new topic for me. Appreciate you facilitating the learning process :-)

More "icing on the cake", chocolate or vanilla?

We did find the elusive Si-Ge layer and more for the NIST 2000 SRM in 2D and real time. All we need now are the AFM, SEM & TEM data for this standard to confirm our analyses and we would have done a decent job of characterizing the Nano structure of this famous universal standard. All with less than 2kW!

https://www.flickr.com/photos/85210325@N04/18504800263/in/dateposted-public/

More awesome XRR data to share! I'll post additional details later. XRR signal from NIST 2000 SRM with Bruker D8 using progressive levels of beam attenuation.

HDRI (High Dynamic Range Imaging) with XRR & XRD? 

XRR data from conventional detectors is also included for comparison and contrast from the same setup without altering the sample position w.r.t. the incident beam.

Just shared with 166 RG members!

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To be fair, similar results are achievable with the Panalytical X'Pert type systems as well. Here is a recent example of Pt thin film on Si (001) substrate:

Real Time 2D Bragg XRD Microscopy with the AXIS-TAS25 Advance XRD Imaging System - 27.7um Pixel, 816x816 Pixels, 12.5fps, 12Bit,

The XRR signal from the above Pt thin film on Si (https://www.flickr.com/photos/85210325@N04/18964697483/in/dateposted-public/) is also  very interesting. Very different from the NIST 2000 SRM as expected. I'll post that XRR data from a comparable Panalytical X'Pert system once I have reviewed thoroughly. The resolution is considerably more limited than the NIST data but never-the-less illustrative. It is exciting to be able to routinely, within minutes, mount to any

Additional resource!

Diffraction and Beyond: Thin Film Analysis by X-Ray Scattering... (Dr. Scott Speakman) - Panalytical

https://www.youtube.com/watch?v=wkusJqpLPMo

Dear Ravi,

Thank you so much for sharing such type of information with us. We definitely need more people with your attitude on Researchgate. The guy in the last video talks about "yesterday lecture" can you share the link to that video as well?   

Not sure Aslan. Please look up on YouTube and post the link here if possible.

Relevant Publications:

"Sequential topography / Rocking Curve Imaging

Plane-wave topography can be made to extract an additional wealth of information from a sample by recording not just one image, but an entire sequence of topographs all along the sample's rocking curve. By following the diffracted intensity in one pixel across the entire sequence of images, local rocking curves from very small areas of sample surface can be reconstructed. Although the required post-processing and numerical analysis is sometimes moderately demanding, the effort is often compensated by very comprehensive information on the sample's local properties. Quantities that become quantitatively measurable in this way include local scattering power, local lattice tilts (crystallite misorientation), and local lattice quality and perfection. Spatial resolution is, in many cases, essentially given by the detector pixel size. The technique of sequential topography, in combination with appropriate data analysis methods also called rocking curve imaging, constitutes a method of microdiffraction imaging, i.e. a combination of X-ray imaging with X-ray diffractometry.

Literature:

1.  •D. Lübbert, T. Baumbach, J. Härtwig, E. Boller, and E. Pernot.  um-resolved high resolution X-ray diffraction imaging for semiconductor quality control. Nucl. Instr. Meth. B (2000) 160(4), 521-527.

2. •J. Hoszowska, A. Freund, E. Boller, J. Sellschop, G. Level, J. Härtwig, R. Burns, M. Rebak, and J. Baruchel. Characterization of synthetic diamond crystals by spatially resolved rocking curve measurements. J.Phys. D:Appl. Phys. (2001) 34, A47-A51.

3. •P. Mikulík, D. Lübbert, D. Korytár, P. Pernot, and T. Baumbach. Synchrotron area diffractometry as a tool for spatial high-resolution three-dimensional lattice misorientation mapping. J.Phys. D:Appl. Phys. (2003) 36(10), A74-A78.

4. •Jeffrey J. Lovelace, Cameron R. Murphy, Reinhard Pahl, Keith Bristerb, and Gloria E. O. Borgstahl: Tracking reflections through cryogenic cooling with topography. J. Appl. Cryst. (2006) 39, 425-432."

https://www.linkedin.com/groups/2683600/2683600-6154677384604897283

https://www.linkedin.com/groups/2683600/2683600-6163698569082654720

https://en.wikipedia.org/wiki/Diffraction_topography

NIST 2000 SRM - Layer Topography!

• Conventional Linear Diffractogram, 
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