Angstrom Evaporator

From USC Nanofab Wiki
Jump to navigation Jump to search

About

Angstrom Engineering e-beam Evaporator in Deposition Bay 1

Process: This is a high-vacuum electron-beam (e-beam) evaporator optimized for depositing thin films of metals and some oxides with excellent control over thickness, uniformity, and adhesion. It supports reactive evaporation (e.g., with O₂) and includes in-situ substrate cleaning via ion milling.

Hardware: 10 kV e-beam gun with 4-pocket crucible turret for multiple materials without breaking vacuum. Variable-angle stage for angled deposition (e.g., shadowing/liftoff). Substrate rotation for improved uniformity. Substrate heater for elevated-temperature deposition. Kaufman-style ion mill source for pre-deposition surface cleaning. Load lock for fast sample exchange without venting main chamber.

Gases:

  • Ar (argon – for ion milling / sputter cleaning)
  • 5% O₂ in Ar (for reactive evaporation of oxides like Al₂O₃)

Film Properties:

  • Ti: Excellent adhesion layer, barrier metal
  • Al: Low-resistivity conductor, optical coatings
  • Al₂O₃: Reactive evaporation for insulating layers (limited rate/selectivity compared to ALD)
  • High directionality (line-of-sight evaporation) – ideal for liftoff processes
  • Good step coverage on moderate topography with rotation/heating

Applications:

  • Metal contacts and interconnects
  • Adhesion/barrier layers (Ti/Al stacks)
  • Reactive oxide deposition (e.g., thin Al₂O₃)
  • Lift-off compatible films
  • Optical/metal coatings
  • Pre-deposition surface cleaning via ion milling

Usage: Vent/load sample via load lock, pump down, perform ion mill clean if needed, select pocket/material, set power/rate, run deposition while monitoring quartz crystal thickness monitor. Use rotation/heating/angle as required. Vent or transfer via load lock.

Detailed Specifications

  • Model: Angstrom Engineering e-beam evaporator
  • Location: Deposition bay 1
  • Substrate size: Up to 6" wafers (pieces/smaller supported)
  • Crucibles: 4 pockets (typically for Ti, Al, Al₂O₃; user-supplied possible)
  • E-beam: 10 kV gun
  • Deposition features:
 * Variable angle stage
 * Substrate rotation
 * Substrate heater (temperature range confirm on tool)
 * Ion mill for substrate cleaning
 * Load lock
  • Gases: Ar, 5% O₂ in Ar
  • Other: Quartz crystal monitor for real-time thickness/rate control, high vacuum base pressure, excellent uniformity with rotation

Documentation

Recipes & Data

  • Standard Processes: Common depositions include:
 * Ti adhesion layer: 10–50 nm at room temp or heated
 * Al conductor: 100–500 nm with rotation
 * Reactive Al₂O₃: Low-rate deposition with 5% O₂/Ar
  • Process Control: Calibrate deposition rates via crystal monitor and post-dep thickness measurement (e.g., Dektak profilometer or ellipsometer). Check uniformity across wafer.
  • Notes: Use ion mill for native oxide removal before metal deposition. Avoid cross-contamination between pockets.

Template:Under review This article was generated with assistance from a large language model (LLM) and is currently under human review and editing. Content may contain inaccuracies, unverified claims, or other issues. Please help improve it.