Angstrom Evaporator

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

• SOP – Standard Operating Procedure
• Training required – contact lab staff (Chandan Ramakrishnaiah or Shivakumar Bhaskaran)

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.