tag:blogger.com,1999:blog-90114331664558077562024-03-05T17:20:13.259-08:00ARP deploys “terahertz sub-surface scanner” to solve the wafer fab’s “reject” problem TeraSpectra_PA_UShttp://www.blogger.com/profile/11666382451956463729noreply@blogger.comBlogger1125tag:blogger.com,1999:blog-9011433166455807756.post-48416566014731597472012-11-17T13:45:00.005-08:002021-02-14T08:50:44.475-08:00ARP deploys 1 Å resolution “terahertz sub-surface scanner” to solve the wafer fab’s “reject” problem <div align="center" class="MsoNormal" style="text-align: center;">
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<span style="font-family: Cambria, serif; font-size: 19px; line-height: 21px;">ARP deploys sub-surface nanoscanner for wafer reject minimization</span></h2>
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<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgaFMu6kFMIUU5ZxM4ZVmxq5v48XS-NNlq7NIWituEZHvF9b5sfCdPGW5x8qji3W6v_nngFX-eeaGDTmYodRTTa8y-Bpmblp91IiuAp6BZGkXspWwd0sqNzom16fpeHNQQJy_L2LnF8s14/s1600/3Dwafer2.jpg" imageanchor="1" style="clear: right; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="335" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgaFMu6kFMIUU5ZxM4ZVmxq5v48XS-NNlq7NIWituEZHvF9b5sfCdPGW5x8qji3W6v_nngFX-eeaGDTmYodRTTa8y-Bpmblp91IiuAp6BZGkXspWwd0sqNzom16fpeHNQQJy_L2LnF8s14/s400/3Dwafer2.jpg" width="400" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">3D image of a segment of a wafer with dies.</td></tr>
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<span style="font-family: Cambria, serif; font-size: 19px; line-height: 21px;">Chip manufacturers (commonly known as fab) face a daunting challenge of keeping the “rejects” down. While a blank wafer cost only a few hundred Dollars, a processed wafer increases its value to hundred thousand Dollars or more depending on the end product. A single reject towards the end of the fab process thus cost a huge amount. This problem is much aggravated when the actual reject number goes up, sometimes as high as 30%. Therefore, controlling the reject number to the lowest is a high priority for the fab industry. To this end, ARP has introduced a non-destructive sub-surface scanner </span><span style="font-family: Cambria, serif; font-size: 14pt; line-height: 115%;">with
a resolution of 1 nm </span><span style="font-family: Cambria, serif; font-size: 19px; line-height: 21px;">by deploying its CW terahertz technology.</span><br />
<span style="font-family: Cambria, serif; font-size: 19px; line-height: 21px;"><br />See full article here: </span><span style="font-family: Cambria, serif;"><span style="font-size: 19px; line-height: 21px;"><a href="http://arphotonics.net/ASMC2014_5.8.pdf" target="_blank">http://arphotonics.net/ASMC2014_5.8.pdf</a> </span></span></div>
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhE7CX8VfWoyn0uYYr5l88bHUmrxSJJ4HJGyi88hRCSpstcH-20i5EnEN_04k873y6qPyl2ec0J7cgjcrCbZsDOpCMld7auf-c6Gfn3g13i1Zv0atZH_RHrkPQdmtUbkkkbHHWubheDcQ4/s1600/wafer1.png" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="300" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhE7CX8VfWoyn0uYYr5l88bHUmrxSJJ4HJGyi88hRCSpstcH-20i5EnEN_04k873y6qPyl2ec0J7cgjcrCbZsDOpCMld7auf-c6Gfn3g13i1Zv0atZH_RHrkPQdmtUbkkkbHHWubheDcQ4/s400/wafer1.png" width="400" /></a></div>
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<span style="font-family: "Cambria","serif"; font-size: 14.0pt; line-height: 115%; mso-ansi-language: EN-US; mso-ascii-theme-font: major-latin; mso-bidi-font-family: "Times New Roman"; mso-bidi-font-size: 11.0pt; mso-bidi-language: AR-SA; mso-bidi-theme-font: minor-bidi; mso-fareast-font-family: Calibri; mso-fareast-language: EN-US; mso-fareast-theme-font: minor-latin; mso-hansi-theme-font: major-latin;">Fig.
1. Intricate patterns on a wafer undergoing fab process.</span></div>
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<div class="MsoNormal" style="margin-top: 12.0pt;">
<span style="font-family: "Cambria","serif"; font-size: 14.0pt; line-height: 115%; mso-ascii-theme-font: major-latin; mso-bidi-font-size: 11.0pt; mso-hansi-theme-font: major-latin;">In the
inspection stage, a wafer is rejected when the accumulated number of defects on
a wafer exceeds the prescribed limit. When
the number of rejected wafers is over the specified number, the lot is rejected
and the inspection stage informs the detection of process excursions. Then the probable cause of excursions is investigated
in the defect sourcing stage. Therefore,
the resolution and accuracy of the inspection system is of crucial importance. However, the current state-of-the-art (SOTA),
high cost and highest sensitivity inspection machine available at the market
place fails to detect defects that are hidden below layers. Consequently, even a wafer passes through the
inspection, the final devices may fail because the inspection system was not able
to detect the smaller and hidden defects.
For example a SOTA inspection system that cost on the order of a million
Dollar, have the highest resolution of <o:p></o:p></span><span style="font-family: Cambria, serif; font-size: 14pt; line-height: 115%;">0.15
µm (150 nm); thus will miss defects smaller than this size.</span><span style="font-family: Cambria, serif; font-size: 14pt; line-height: 115%;"> </span><span style="font-family: Cambria, serif; font-size: 14pt; line-height: 115%;">As the modern fab process is defining feature
sizes down to 60 nm or less, the fab inspection technicians are facing with the
challenge of detecting and identifying defects that are only a few nanometers
in dia.</span><span style="font-family: Cambria, serif; font-size: 14pt; line-height: 115%;"> </span><span style="font-family: Cambria, serif; font-size: 14pt; line-height: 115%;">The TeraScan from ARP addresses
this deficiency by introducing a resolution of 1 nm.</span></div>
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhMvV3xQyi9oFr_vXEH3qCTHtvQI8ctXHve8vML9Hef-31QxH5G-EJgAbc9MKc_5S6qDp4_VLKYp7iPFIDAVDS4u2KNEKxHn9X-MxB60rXO_fMMJ8NHGUGM1mbLevy9oi0kTWHJzG8qV44/s1600/thz.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="162" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhMvV3xQyi9oFr_vXEH3qCTHtvQI8ctXHve8vML9Hef-31QxH5G-EJgAbc9MKc_5S6qDp4_VLKYp7iPFIDAVDS4u2KNEKxHn9X-MxB60rXO_fMMJ8NHGUGM1mbLevy9oi0kTWHJzG8qV44/s640/thz.jpg" width="640" /></a></div>
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<span style="font-family: "Cambria","serif"; font-size: 14.0pt; line-height: 115%; mso-ascii-theme-font: major-latin; mso-bidi-font-size: 11.0pt; mso-hansi-theme-font: major-latin;">Fig.
2. Position of terahertz is in between the microwave and infra-red (IR).<o:p></o:p></span></div>
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<span style="font-family: "Cambria","serif"; font-size: 14.0pt; line-height: 115%; mso-ansi-language: EN-US; mso-ascii-theme-font: major-latin; mso-bidi-font-family: "Times New Roman"; mso-bidi-font-size: 11.0pt; mso-bidi-language: AR-SA; mso-bidi-theme-font: minor-bidi; mso-fareast-font-family: Calibri; mso-fareast-language: EN-US; mso-fareast-theme-font: minor-latin; mso-hansi-theme-font: major-latin;"><br /></span></div>
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<span style="font-family: "Cambria","serif"; font-size: 14.0pt; line-height: 115%; mso-ansi-language: EN-US; mso-ascii-theme-font: major-latin; mso-bidi-font-family: "Times New Roman"; mso-bidi-font-size: 11.0pt; mso-bidi-language: AR-SA; mso-bidi-theme-font: minor-bidi; mso-fareast-font-family: Calibri; mso-fareast-language: EN-US; mso-fareast-theme-font: minor-latin; mso-hansi-theme-font: major-latin;">Another
issue is detecting very small defects that are embedded in the sub-surface
layers. Modern fab processes involve
layer-by-layer construction and defining devices on a wafer (the so called
bottom-up process) where tens of layers are stacked one on top of the previous. Common optical inspection system can see only
on the surface and the resolution is limited. Thus, defects buried under the top surface
must be detected early in the process before it progresses towards completion. This is not possible by instruments built
around visible light or IR which is offered by the current SOTA. </span></div>
<div class="MsoNormal" style="text-align: left;">
</div>
<div class="MsoNormal" style="margin-top: 12.0pt; mso-pagination: none;">
<span style="font-family: "Cambria","serif"; font-size: 14.0pt; line-height: 115%; mso-ascii-theme-font: major-latin; mso-bidi-font-size: 11.0pt; mso-hansi-theme-font: major-latin;">Terahertz
portion of the electromagnetic spectrum (Fig. 1) provides some unique features
that are not available from other sources.
Terahertz can penetrate most materials except metals; thus, it provides
the opportunity to inspect not only the surface but also the sub-surface
interior layers of a multi-layered substrate.
Unlike X-ray, terahertz is non-ionizing; therefore, it does not perturb
or damage delicate features which in some cases are only a few nanometers. Yet, because of its very high sensitivity,
terahertz can detect defects of nanometer size. </span><span style="font-family: Cambria, serif; font-size: 14pt; line-height: 115%;">These
combination of terahertz properties and a smart positioning system incorporated
in ARP’s terahertz inspection, provides unique opportunity to successfully inspect
wafers at early stage of defect formation as well as after-process device
failure analysis.</span><span style="font-family: Cambria, serif; font-size: 14pt; line-height: 115%;"> Once the fab technicians are able to identify
the cause of defect formation, appropriate measure may be taken to prevent its
reoccurrences. ARP’s terahertz scanner
is designed to help exactly this situation.
Sample data are shown below. Fig.
3 shows that the scanning resolution is 1 nm and difference between adjacent
layers are detectable. Fig. 4 shows the
reconstructed surface texture generated from a series of surface scan. Any defects such as, inclusions, cracks,
non-uniformity, or very small particulate material can be clearly detected and
identified by this technique.</span></div>
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<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhcWYlqHXzpqkaxCLxQPTeKUCw6NkbncUt3I2CcTHNUiZQzHC_u_He7AHAF5hF10Q8j80XWSPfxb13_9BuZlE89MXq0xn9fba151LGj24mIAXPBAoQhwn1ZGjZ0bJ3x_MxbnVJUNUTOZ6M/s1600/res1nm.png" imageanchor="1" style="display: inline !important; margin-left: auto; margin-right: auto; text-align: center;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhcWYlqHXzpqkaxCLxQPTeKUCw6NkbncUt3I2CcTHNUiZQzHC_u_He7AHAF5hF10Q8j80XWSPfxb13_9BuZlE89MXq0xn9fba151LGj24mIAXPBAoQhwn1ZGjZ0bJ3x_MxbnVJUNUTOZ6M/s1600/res1nm.png" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="font-family: Cambria, serif; font-size: 19px; line-height: 21px;">Fig. 3. Scan resolution ~1 nm showing two separate layers.</span></td></tr>
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<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhQzrMhyphenhyphenY3pUSWZJSgQUVMCAVN5NrQt9WYoE5t42U7q7B2tld0d7DknBQP8SUaRAlPKL-p7y5NVWLG3_XnWGPyOmCLdYXQyiI_arPojB0_yh26hzun5pctA_KevQbx2oQTAf9erCbxVA6Y/s1600/reconsurf.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="323" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhQzrMhyphenhyphenY3pUSWZJSgQUVMCAVN5NrQt9WYoE5t42U7q7B2tld0d7DknBQP8SUaRAlPKL-p7y5NVWLG3_XnWGPyOmCLdYXQyiI_arPojB0_yh26hzun5pctA_KevQbx2oQTAf9erCbxVA6Y/s400/reconsurf.jpg" width="400" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="font-family: Cambria, serif; font-size: 14pt; line-height: 115%;">Fig.
4. Reconstructed surface texture generated from a series of surface scan.</span><br />
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<b><u><span style="font-family: 'Bookman Old Style', serif; font-size: 13.5pt; line-height: 115%;">About
Applied Research & Photonics</span></u></b><span style="font-size: 13.5pt; line-height: 115%;"><o:p></o:p></span></div>
<div class="MsoNormal">
<span style="font-family: 'Bookman Old Style', serif; font-size: 13.5pt;">Located
in Harrisburg, PA, Applied Research & Photonics, Inc. (ARP) is a
nanotechnology company with the core products in the terahertz area.<span class="apple-converted-space"> </span> ARP has demonstrated a number of
products based on its proprietary dendrimer nanotechnology.<span class="apple-converted-space"> </span> ARP’s terahertz spectrometer,
TeraSpectra, uses a high-power terahertz source enabling high resolution
spectrometry.<span class="apple-converted-space"> </span> It has a wider
terahertz range (up to ~30 THz) for probing molecular phenomena on time scales
from a few femto-seconds to a few tens of pico-seconds.<span class="apple-converted-space"> </span> Designed and manufactured in
Harrisburg, TeraSpectra offers the capability of solving a </span><span style="font-family: "Cambria","serif"; font-size: 14.0pt; mso-ascii-theme-font: major-latin; mso-bidi-font-size: 11.0pt; mso-hansi-theme-font: major-latin;"><o:p></o:p></span><span style="font-family: 'Bookman Old Style', serif; font-size: 13.5pt;">number
of problems in biomolecular, pharmaceutical, analytical and other research
areas.<span class="apple-converted-space"> </span> ARP is also working
with the US Department of Homeland Security to develop remote detection of
explosives for anti-terrorism applications. <span class="apple-converted-space"> </span>For more information, visit ARP web
site at:<span class="apple-converted-space"> </span></span><a href="http://www.arphotonics.net/"><span style="font-family: "Bookman Old Style","serif"; font-size: 13.5pt;">www.arphotonics.net</span></a><span class="apple-converted-space"><span style="font-family: 'Bookman Old Style', serif; font-size: 13.5pt;"> </span></span><span style="font-family: 'Bookman Old Style', serif; font-size: 13.5pt;">or contact:</span></div>
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<span style="font-family: 'Bookman Old Style', serif; font-size: 13.5pt;">Anis Rahman, PhD</span><span style="font-size: 13.5pt;"><o:p></o:p></span></div>
<div class="MsoNormal" style="margin-bottom: 0.0001pt;">
<b><span style="font-family: 'Bookman Old Style', serif; font-size: 13.5pt;">Applied Research and Photonics, Inc.</span></b><span style="font-size: 13.5pt;"><o:p></o:p></span></div>
<div class="MsoNormal" style="margin-bottom: 0.0001pt;">
<span style="font-family: 'Bookman Old Style', serif; font-size: 13.5pt;">470 Friendship Road, Suite 10</span><span style="font-size: 13.5pt;"><o:p></o:p></span></div>
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<span style="font-family: 'Bookman Old Style', serif; font-size: 13.5pt;">Harrisburg, PA 17111, USA</span><span style="font-size: 13.5pt;"><o:p></o:p></span></div>
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<span style="font-family: 'Bookman Old Style', serif; font-size: 13.5pt;">Phone: +1 (717) 623-8201</span><span style="font-size: 13.5pt;"><o:p></o:p></span></div>
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<span style="font-family: 'Bookman Old Style', serif; font-size: 13.5pt;">Email:<span class="apple-converted-space"> </span></span><a href="mailto:info@arphotonics.net"><span style="font-family: "Bookman Old Style","serif"; font-size: 13.5pt;">info@arphotonics.net</span></a><span style="font-family: "Bookman Old Style","serif"; mso-bidi-font-family: "Courier New";">
<o:p></o:p></span></div>
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