Jordan Valley Semiconductors (JVS) develops, serves, manufactures and sells X-ray and VUV metrology solutions (XRF, XRR, XRD, WAXRD,HRXRD,SAXS & VUV) to semiconductors manufacturers, such as logic (IDM and foundries)and memory (DRAM, Flash) fabs as well as hard disk drives, HBLED fabs and other compound semiconductors and related fields. Our metrology tools cover front end of the line (FEOL - SiGe, HiK, Metal gate), back end of the line (BEOL - Copper Seed Barrier, Tungsten and Aluminum) wafer level packaging (UBM and Micro bumps) and many others. http://www.jvsemi.com/applications/16-wafer-level-packaging 2019-09-16T03:38:10+00:00 Joomla! - Open Source Content Management 2012-08-30T10:35:11+00:00 2012-08-30T10:35:11+00:00 http://www.jvsemi.com/applications/wafer-level-packaging/ubm-rdl-and-micro-bumps Graeme Gibson [email protected]

<div class="feed-description"><p>{tab=UBM}</p> <ul> <li>Small bumps using Sn rich solder makes the UBM selection more critical <ul> <li>Surface tension is increasingly impacted by wettability</li> </ul> </li> <li>Reduced solder ball size increases surface to volume ratio <ul> <li>Surface tension is increasingly impacted by wettability</li> <li>Past Cu-Cr-based UBM is not compatible</li> </ul> </li> <li>Nickel based UBM materials are desired because of the low reaction rate with Sn <ul> <li>Many Ni based UBM stacks are being used</li> </ul> </li> <li>Electroless acidic hypophosphite baths are used for nickel deposition <ul> <li>If the phosphorus content is high (&gt;9.5 atm%), the Ni(P) will be in the amorphous state</li> <li>Suppresses fast grain-boundary diffusion</li> </ul> </li> </ul> <p><strong>XRF data for UBM and RDL stacks</strong></p> <ul> <li>Typical UBM and RDL layers are multi-layer stacks: <ul> <li>Barrier (or Under Metal)/Bulk Metal Layer / Passivation Metal Layer</li> </ul> </li> <li>Common UBM Film Stack Variations <ul> <li>Al/Ni/Au, Al/Ni/Cu</li> <li>Cu/Ni/Au, Cu/Ni/Pd</li> <li>Ti/Ni/Au, Ti/Cu/Ni/Au, Ti-W/Cu/Cu</li> <li>Cr/Cu/Cu, Cr/Cu/Cu/Ni</li> </ul> </li> </ul> <p style="text-align: center;"><img src="images/applications/UBMRDLBumps/Apps17.png" width="433" height="91" alt="Apps17" /></p> <p><strong>Why control bump composition?</strong></p> <p style="text-align: center;"><img src="images/applications/UBMRDLBumps/Apps18.png" width="433" height="271" alt="Apps18" /></p> <p>WLP represents a rapidly growing market segment due to the need for high-density, high-pin-count, smaller size, stacked and high performance devices. This growth gives rise to new metrology challenges with re-distribution and under bump metallization film stacks. In addition, lead-free bumps also require in-line control of material composition.</p> <p>Jordan Valley stands uniquely qualified to address these continually evolving metrology needs with industry-leading small spot, high speed X-ray Fluorescence technology.</p> <p>{tab=RDL &amp; Bumps}</p> <p><strong>Semiconductor manufacturers face many key emerging trends in WLP. These include:</strong></p> <ul> <li>Redistribution Layers</li> <li>New UBM Films and Stacks</li> <li>Tighter Pitch Features</li> <li>Smaller Solder Balls</li> <li>Lead-Free Solder Alternatives</li> <li>These critical trends create associated metrology challenges, and generate the need for:</li> </ul> <p style="text-align: center;"><img src="images/applications/UBMRDLBumps/Apps16.png" width="433" height="343" alt="Apps16" /></p> <ul> <li>Thickness and composition control</li> <li>High sampling and high throughput</li> <li>Fewer blanket wafers</li> <li>Production wafer sampling</li> </ul> <p>These needs drive the demand for non-destructive thickness measurements on RDL and UBM layers that include a small spot measurement technique with excellent spot placement, with tighter pitch densities (&lt;200μm), and smaller solder balls (&lt;100μm).</p> <p><strong>Other key considerations are composition measurements on the bulk UBM layer, where Ni(P) composition impacts the quality of the passivation layer, and composition measurements of lead-free solder alternatives:</strong></p> <ul> <li>Sn/Ag composition → impacts reliability / prevents "shorts"</li> <li>Sn/Ag has shown to gain Ni or Cu from the UBM during the reflow process</li> </ul> <p>XRF technology from Jordan Valley answers these challenges via energy dispersive (~150eV) techniques with multi-detector array for fast, high-throughput measurements and 100% detector efficiency for Sn/Ag, plus small spot (poly-capillary) optics capable of measuring down to 50x50μm features. In addition, Jordan Valley XRF technology offers non-destructive real-time measurements that deliver immediate turn around.</p> <p>{/tabs}</p></div>

<div class="feed-description"><p>{tab=UBM}</p> <ul> <li>Small bumps using Sn rich solder makes the UBM selection more critical <ul> <li>Surface tension is increasingly impacted by wettability</li> </ul> </li> <li>Reduced solder ball size increases surface to volume ratio <ul> <li>Surface tension is increasingly impacted by wettability</li> <li>Past Cu-Cr-based UBM is not compatible</li> </ul> </li> <li>Nickel based UBM materials are desired because of the low reaction rate with Sn <ul> <li>Many Ni based UBM stacks are being used</li> </ul> </li> <li>Electroless acidic hypophosphite baths are used for nickel deposition <ul> <li>If the phosphorus content is high (&gt;9.5 atm%), the Ni(P) will be in the amorphous state</li> <li>Suppresses fast grain-boundary diffusion</li> </ul> </li> </ul> <p><strong>XRF data for UBM and RDL stacks</strong></p> <ul> <li>Typical UBM and RDL layers are multi-layer stacks: <ul> <li>Barrier (or Under Metal)/Bulk Metal Layer / Passivation Metal Layer</li> </ul> </li> <li>Common UBM Film Stack Variations <ul> <li>Al/Ni/Au, Al/Ni/Cu</li> <li>Cu/Ni/Au, Cu/Ni/Pd</li> <li>Ti/Ni/Au, Ti/Cu/Ni/Au, Ti-W/Cu/Cu</li> <li>Cr/Cu/Cu, Cr/Cu/Cu/Ni</li> </ul> </li> </ul> <p style="text-align: center;"><img src="images/applications/UBMRDLBumps/Apps17.png" width="433" height="91" alt="Apps17" /></p> <p><strong>Why control bump composition?</strong></p> <p style="text-align: center;"><img src="images/applications/UBMRDLBumps/Apps18.png" width="433" height="271" alt="Apps18" /></p> <p>WLP represents a rapidly growing market segment due to the need for high-density, high-pin-count, smaller size, stacked and high performance devices. This growth gives rise to new metrology challenges with re-distribution and under bump metallization film stacks. In addition, lead-free bumps also require in-line control of material composition.</p> <p>Jordan Valley stands uniquely qualified to address these continually evolving metrology needs with industry-leading small spot, high speed X-ray Fluorescence technology.</p> <p>{tab=RDL &amp; Bumps}</p> <p><strong>Semiconductor manufacturers face many key emerging trends in WLP. These include:</strong></p> <ul> <li>Redistribution Layers</li> <li>New UBM Films and Stacks</li> <li>Tighter Pitch Features</li> <li>Smaller Solder Balls</li> <li>Lead-Free Solder Alternatives</li> <li>These critical trends create associated metrology challenges, and generate the need for:</li> </ul> <p style="text-align: center;"><img src="images/applications/UBMRDLBumps/Apps16.png" width="433" height="343" alt="Apps16" /></p> <ul> <li>Thickness and composition control</li> <li>High sampling and high throughput</li> <li>Fewer blanket wafers</li> <li>Production wafer sampling</li> </ul> <p>These needs drive the demand for non-destructive thickness measurements on RDL and UBM layers that include a small spot measurement technique with excellent spot placement, with tighter pitch densities (&lt;200μm), and smaller solder balls (&lt;100μm).</p> <p><strong>Other key considerations are composition measurements on the bulk UBM layer, where Ni(P) composition impacts the quality of the passivation layer, and composition measurements of lead-free solder alternatives:</strong></p> <ul> <li>Sn/Ag composition → impacts reliability / prevents "shorts"</li> <li>Sn/Ag has shown to gain Ni or Cu from the UBM during the reflow process</li> </ul> <p>XRF technology from Jordan Valley answers these challenges via energy dispersive (~150eV) techniques with multi-detector array for fast, high-throughput measurements and 100% detector efficiency for Sn/Ag, plus small spot (poly-capillary) optics capable of measuring down to 50x50μm features. In addition, Jordan Valley XRF technology offers non-destructive real-time measurements that deliver immediate turn around.</p> <p>{/tabs}</p></div>