Plasma Atomic Layer Deposition Processes and Thermal ALD—FlexAL

With maximum flexibility in precursors, process gases, and hardware design inside a single process chamber, the FlexAL atomic layer deposition (ALD) system provides a wide range of optimized high-quality plasma ALD and thermal ALD procedures.

Maximum flexibility in the choice of precursors, process gases, hardware features, and options

Optimized to maintain low-damage, high-quality substrates

Removable liners enable easy chamber maintenance

Remote plasma for low-damage plasma ALD combined with thermal ALD in one deposition chamber

RF-biased electrode option available for control of film properties

Industry-standard cassette-to-cassette handling for higher throughput

Low temperature to facilitate high-quality deposition on temperature-sensitive surfaces

Overview

The ALD product line includes a variety of instruments to satisfy different needs of small-scale manufacturing, corporate R&D, and academia. There is a substantial process library at Oxford Instruments, and new processes are constantly being developed.

All ALD tools come with free lifetime process support, which includes new process recipes, guidance on creating new materials, and access to the most recent ALD process advancements.

Plasma ALD methods depend heavily on ions. Ions can enhance the quality of films, especially when used with nitrides and at lower deposition temperatures. But some substrates and interfaces could be ion-sensitive, which might harm the device.

With a sophisticated plasma source and automated matching unit (AMU), the FlexAL ALD system accurately regulates plasma ions, allowing the plasma to be used at its full potential while avoiding damage.

Features

Chamber ports/windows for the integration of in-situ analysis equipment, e.g. ellipsometry

Automated single-wafer load-lock for loading substrates up to 200 mm

Clusterable with additional process modules with vacuum transfer between chambers

Fully illustrated precursor exchange procedures with checklists

Cleanroom interface available for through-wall installation

Ozone generator available for integration

Wide range of electrode options-grounded and biased electrodes

Turbomolecular pump benefits moisture-sensitive nitrides and metals

RF table bias option for film property enhancements such as conductivity, crystallinity, stress control

Image Credit: Oxford Instruments Plasma Technology

Applications

Superconducting nitrides for quantum devices (e.g., TiN, NbN)

High-quality high-k gate oxides for graphene passivation (e.g., titanium oxide, silicon oxide, gallium oxide)

GaN HEMT pre-treatment and passivation

ALD of 2D transition metal dichalcogenides (TMDCs)

Pinhole-free passivation layers for OLEDs and polymers

Passivation of crystalline silicon solar cells

Highly conformal coatings for microfluidic devices

ALD moisture barriers and passivation of sensitive substrates

Conformal deposition of SiO₂, TiO₂, and Al₂O₃ by Plasma ALD, (CC BY 4.0 license), image library at www.AtomicLimits.com, 2021. Image Credit: Oxford Instruments Plasma Technology

High conformality of plasma ALD Al₂O₃ (left image) and SiO₂ (right image). Image Credit: Eindhoven University of Technology.

Specifications

Wafer size: up to 200 mm

Temperature range: From 30 up to 550 °C (with table bias)

Precursors

Precursor options for research (up to 100 g) and production (up to 500 g)

Up to 10 plasma and thermal gas precursors

Up to eight metal liquid or solid rapid bubbled precursors

Ozone generator optional

Water pot standard

Cluster with: PECVD, ICPCVD, RIE, and Sputter modules

Options

FlexAL2D

The FlexAL2D system offers a variety of advantages for creating 2D materials and delivers ALD of 2D transition metal dichalcogenides (TMDCs) for nanodevice applications.

2D Materials Growth

At CMOS-compatible temperatures

Over a large area (200 mm wafers)

With precise digital thickness control

Robust ALD Processes for 2D Materials

Self-limiting ALD growth.

Oxygen- and carbon-free (< 2%)

MoS₂

High growth per cycle ~0.1 nm/cycle

Crystalline material above 300 °C

Tunable Morphology

Control over basal plane or edge plane orientation

Create advanced 2D device structures

RF substrate biasing option for film property control

Growth of ALD dielectrics and other ALD layers on 2D materials in one tool