Edge Rounding is a wafer finishing process that smooths sharp corners at the wafer edge to reduce chipping, particle generation, and film stress during processing.

What Is Edge Rounding?

• Method: Chemical-mechanical polishing or wet etching of wafer bevel
• Profile: Transitions sharp 90° corner to rounded ~45° bevel
• Timing: After wafer slicing, before device processing
• Specification: Typically 200-400μm radius

Why Edge Rounding Matters

Sharp wafer edges concentrate mechanical stress, leading to chips that contaminate entire lots. Rounded edges reduce breakage by 50%+ during handling.

<svg viewBox="0 0 401 207" xmlns="http://www.w3.org/2000/svg" style="max-width:100%;height:auto" role="img"><rect x="0" y="0" width="401" height="207" rx="12" fill="#0d1117"/><g font-family="ui-monospace,SFMono-Regular,Menlo,Consolas,&quot;Liberation Mono&quot;,monospace" font-size="14"><text xml:space="preserve" x="20" y="31.7"><tspan fill="#c9d1d9">Wafer Edge Profiles:</tspan></text><text xml:space="preserve" x="20" y="50.7"><tspan fill="#c9d1d9">Sharp Edge (as-sliced):    Rounded Edge:</tspan></text><text xml:space="preserve" x="20" y="69.7"><tspan fill="#c9d1d9">      </tspan><tspan fill="#6e7681">│</tspan><tspan fill="#c9d1d9">  </tspan><tspan fill="#6e7681">│</tspan><tspan fill="#c9d1d9">                    ╭</tspan><tspan fill="#6e7681">──</tspan><tspan fill="#c9d1d9">╮</tspan></text><text xml:space="preserve" x="20" y="88.7"><tspan fill="#c9d1d9">      </tspan><tspan fill="#6e7681">│</tspan><tspan fill="#c9d1d9">  </tspan><tspan fill="#6e7681">│</tspan><tspan fill="#c9d1d9">                   ╱    ╲</tspan></text><text xml:space="preserve" x="20" y="107.7"><tspan fill="#c9d1d9">      </tspan><tspan fill="#6e7681">│</tspan><tspan fill="#c9d1d9">  </tspan><tspan fill="#6e7681">│</tspan><tspan fill="#c9d1d9">                  ╱      ╲</tspan></text><text xml:space="preserve" x="20" y="126.7"><tspan fill="#c9d1d9">      </tspan><tspan fill="#6e7681">│</tspan><tspan fill="#c9d1d9">  </tspan><tspan fill="#6e7681">│</tspan><tspan fill="#c9d1d9">                 </tspan><tspan fill="#6e7681">│</tspan><tspan fill="#c9d1d9">        </tspan><tspan fill="#6e7681">│</tspan></text><text xml:space="preserve" x="20" y="145.7"><tspan fill="#6e7681">══════</tspan><tspan fill="#c9d1d9">╯  </tspan><tspan fill="#6e7681">╚═══════</tspan><tspan fill="#c9d1d9">       </tspan><tspan fill="#6e7681">═══</tspan><tspan fill="#c9d1d9">╯        </tspan><tspan fill="#6e7681">╚═══</tspan></text><text xml:space="preserve" x="20" y="164.7"><tspan fill="#c9d1d9">90° corners              Smooth transitions</tspan></text><text xml:space="preserve" x="20" y="183.7"><tspan fill="#c9d1d9">Chip/crack prone         Stress-free</tspan></text></g></svg>

Edge Rounding Benefits:

• Reduced edge chipping during robot handling
• Better epitaxial film uniformity at edge
• Reduced particle generation during CMP
• Lower film stress at wafer periphery
• Fewer handling-related scratches