Ar-ion inside an evaporator and deposited metal contacts 

Deposited Metal Contacts (AR Ion & Thermal/E-Beam Evaporation)

We deposit high-purity metal films for ohmic and Schottky contacts on silicon, compound semiconductors, glass, quartz, and sapphire. Processes are optimized for clean lift-off, excellent adhesion, and low contact resistance with precise thickness control.

Typical Stacks & Use Cases

• Adhesion + Au: Ti/Au, Cr/Au for bond pads, interconnects, wire-bonding
• Low-resistivity Al-based: Ti/Al/Ni/Au for Si/SiC ohmic contacts
• Schottky contacts: Ni/Au, Pt/Au for detectors and diodes
• Barrier stacks: Ti/Pt/Au or Ti/W/Au for diffusion and electromigration control
• Seed layers for subsequent electroplating (Cu, Ni, Au)

Process Capabilities

• Methods: AR ion cleaning, thermal & e-beam evaporation (multi-pocket)
• Thickness: ~5 nm to ~2 µm (stack-dependent)
• Uniformity: ±3–8% typical across 100–200 mm; 300 mm on request
• Rates: Lift-off-friendly low rates for fine features; higher rates for blanket metal
• Adhesion prep: in-situ AR ion mill/etch for native oxide removal
• Stress control: tuned by rate, power, and substrate temperature

Design for Fabrication

• Lift-off: undercut resists (e.g., bilayer) recommended for ≥300 nm Au
• Lines/Spaces: successful down to sub-micron with controlled rates and angles
• Step coverage: evaporation is directional; consider angled deposit or thicker adhesion layer
• Anneals: optional RTA/furnace steps for ohmic formation (stack-specific)

Substrates We Support

• Si (CZ, FZ, SOI), SiC, GaAs, GaN/Si, InP
• Glass: fused silica, BK7, Borofloat, D263, ITO-coated glass
• Sapphire and quartz single crystal

Metrology & Documentation

• Thickness by QCM/ellipsometry/profilometry (as applicable)
• Sheet resistance (Rs) for conductive stacks
• Adhesion & visual inspection; microscope photos on request

FAQs

Can you do lift-off? Yes—rates and substrate temperature are tuned for clean lift-off.

What metal purity? 99.99%–99.999% sources depending on metal.

Do you offer patterned contacts? Yes—use your mask & resist process; we handle the deposition.

Learn more about substrates: Silicon, SiC, GaAs, Fused Silica, Sapphire.

Deposited Metal Contacts (AR Ion, E-Beam, and Thermal Evaporation)

UniversityWafer provides precision metal contact deposition services for semiconductor, MEMS, and photonic device fabrication. We specialize in ohmic and Schottky contact formation using high-purity metal evaporation in ultra-high-vacuum (UHV) systems equipped with AR ion cleaning, multi-pocket e-beam sources, and quartz crystal monitoring for exact film thickness control.

Purpose and Applications

Deposited metal contacts provide the electrical interface between device layers and the external circuit. High-quality metallization ensures low contact resistance, thermal stability, and excellent adhesion—critical for power electronics, RF devices, sensors, and optoelectronic components.

• Silicon & SiC ohmic contacts for diodes and transistors
• GaAs/GaN Schottky contacts for detectors and HEMTs
• Bond pads and interconnects for MEMS or CMOS packaging
• Seed and barrier layers for electroplating and diffusion control

Available Metals and Stack Options

• Gold-based: Ti/Au, Cr/Au, Ni/Au for low-resistance pads
• Aluminum-based: Ti/Al/Ni/Au for Si, SiC, GaN devices
• Barrier stacks: Ti/Pt/Au, Ti/W/Au for thermal stability
• Specialty metals: Ag, Mo, Ta, W, Pd, Pt, Cu, Ni, Co
• Custom multi-layer sequences available upon request

Deposition Techniques

• Thermal Evaporation: gentle heating for low-melting metals (Al, Ag)
• E-Beam Evaporation: high precision, dense films, ideal for noble metals
• AR Ion Cleaning: pre-deposition surface activation and oxide removal
• In-Situ Layer Stacking: sequential metal deposition without vacuum break
• In-situ Ar-ion cleaning inside the evaporator: Removes native oxides directly within the deposition chamber before metal evaporation, ensuring pristine interfaces and improved adhesion.

Film & Process Specifications

• Thickness range: 5 nm – 3 µm (±3–5% uniformity across 100–200 mm)
• Deposition rates: 0.5–3 Å/s for lift-off, up to 10 Å/s for blanket coating
• Vacuum level: ≤ 1×10⁻⁶ Torr base pressure
• Substrate size: 100–200 mm standard; 300 mm optional
• Substrate temperature: RT–250 °C (controlled)

Metrology & Quality Control

• Thickness verification via profilometer or ellipsometer
• Sheet resistance (Rs) mapping for conductive films
• Surface morphology and grain analysis (optical microscopy)
• Optional SEM or AFM for research documentation

Post-Deposition Processing

• Lift-off compatible process with controlled rate and angle
• RTA or furnace annealing for ohmic contact formation
• Wire-bonding tests and visual inspection on request

Substrates Supported

• Silicon (CZ, FZ, SOI), SiC, GaAs, GaN/Si, InP
• Glass: BK7, Borofloat 33, D263, fused silica, ITO glass
• Sapphire, quartz, and LiNbO₃ for photonic components

Advantages of AR Ion & E-Beam Evaporated Contacts

• Superior adhesion and purity due to in-situ pre-cleaning
• High density and smoothness for low-resistance interfaces
• Controlled stoichiometry and reproducible layer thickness
• Low contamination and film stress

Documentation and Lead Times

Each run includes detailed process records: base pressure, deposition rate, metal source batch, and substrate ID. Standard turnaround is 3–5 business days for R&D lots; production scaling available.

Related services: Metal Deposition | Silicon Wafers | Sapphire Wafers | SiC Substrates.