Edge Trim is a wafer process step that removes material from the wafer edge to eliminate particles, films, or defects that could cause contamination or handling issues.

What Is Edge Trim?

• Method: Chemical etching or mechanical grinding of outer 1-3mm
• Purpose: Remove edge bead, prevent film delamination, reduce particles
• Timing: After film deposition, CMP, or photoresist coating
• Equipment: Spin processors with edge-targeted nozzles

Why Edge Trim Matters

Film buildup at wafer edges causes particles during handling and robot contact. Edge trim maintains clean handling surfaces throughout the process flow.

<svg viewBox="0 0 435 226" xmlns="http://www.w3.org/2000/svg" style="max-width:100%;height:auto" role="img"><rect x="0" y="0" width="435" height="226" 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 Cross-Section at Edge:</tspan></text><text xml:space="preserve" x="20" y="50.7"><tspan fill="#c9d1d9">Before Edge Trim:       After Edge Trim:</tspan></text><text xml:space="preserve" x="20" y="69.7"><tspan fill="#c9d1d9">      Film buildup           Clean edge</tspan></text><text xml:space="preserve" x="20" y="88.7"><tspan fill="#c9d1d9">           </tspan><tspan fill="#6e7681">↓</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></text><text xml:space="preserve" x="20" y="145.7"><tspan fill="#c9d1d9">  </tspan><tspan fill="#6e7681">│</tspan><tspan fill="#c9d1d9">   WAFER     </tspan><tspan fill="#6e7681">│</tspan><tspan fill="#c9d1d9">       </tspan><tspan fill="#6e7681">│</tspan><tspan fill="#c9d1d9">   WAFER     </tspan><tspan fill="#6e7681">│</tspan></text><text xml:space="preserve" x="20" y="164.7"><tspan fill="#c9d1d9">   ╲            ╱         ╲            ╱</tspan></text><text xml:space="preserve" x="20" y="183.7"><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="202.7"><tspan fill="#c9d1d9">  Edge bead risk         Particle-free handling</tspan></text></g></svg>

Edge Trim Methods: