GLAD process

Structuring of thin films by GLancing Angle Deposition (GLAD)

The GLAD technique is an original approach for structuring of thin films. Some complex architectures can be produced by this technique with a variety of materials including metals, oxides, nitrides and so on. Various geometries can be reached such as inclined columns, zigzags, spirals ... Dimensions and sizes of these shapes can also be modified adjusting therelevant parameters of the process such as deposition pressure, incidence angle of particles impinging on the growing film, substrate rotation speed, initial characteristics of the substrate (temperature, roughness, patterning). The added value of these structured thin films results in broadening the spectrum of their physical and mechanical properties compared to filmsdeposited by conventional normal incidence.

Scheme of the GLAD process. By changing incidence angle and substrate rotation, various architectures can be produced

Architectures at the micro- and nano-scales produced by GLAD

Photographs below show some observations performed by SEM on the cross section of the films deposited by sputtering. Normal columns (a), inclined columns (b), zigzags (c) or spirals (d) can be produced by adjusting the deposition parameters.

SEM cross-section views of metallic films produced by GLAD sputtering. Chromium films exhibiting a) normal and b) inclined columns. Vanadium films with c) spiral and d) zigzag architectures

GLAD co-sputtering with 2 targets

Two facing targets can be simultaneously sputtered with the same angle. A growth competition occurs between A nd B particle flux. A two-component structure can be produced (Janus-like structure).

Scheme of the GLAD co-sputtering process involving 2 facing targets.

Inclined columns, zigzags and spirals with a two-component columnar structure can also be fabricated

Growth by Monte Carlo simulations

These simulations are performed with a home made software: SIMUL3D. They do not only lead to visualize the dynamics of growth produced by GLAD, they also provide relevant information on the structural and morphological characteristics of the deposited films like density versus thickness, surface roughness, density of nucleation, columns size, ... Few examples of videos illustrating the growth of thin films by GLAD are shown below.

Conventional growth of columnar structure

Inclined columns

Periodic zigzag columns