5 research outputs found
Changes in supply chain management approach with new work force of millennial's
The growth, chemical, structural, mechanical, and optical properties of oxide thin films deposited by plasma enhanced atomic layer deposition (PEALD) are strongly influenced by the average-bias voltage applied during the reaction step of surface functional groups with oxygen plasma species. Here, this effect is investigated thoroughly for SiO2 deposited in two different PEALD tools at average-bias voltages up to −300 V. Already at a very low average-bias voltage (< −10 V), the SiO2 films have significantly lower water content than films grown without biasing together with the formation of denser films having a higher refractive index and nearly stoichiometric composition. Substrate biasing during PEALD also enables control of mechanical stress. The experimental findings are supported by density functional theory and atomistic simulations. They demonstrate that the application of an electric field during the plasma step results in an increased energy transfer between energetic ions and the surface, directly influencing relevant surface reactions. Applying an electric field during the PEALD process leads to SiO2 thin films with significantly improved properties comparable to films grown by ion beam sputtering
Tuning Material Properties of Oxides and Nitrides by Substrate Biasing during Plasma-Enhanced Atomic Layer Deposition on Planar and 3D Substrate Topographies
Oxide
and nitride thin-films of Ti, Hf, and Si serve numerous applications
owing to the diverse range of their material properties. It is therefore
imperative to have proper control over these properties during materials
processing. Ion-surface interactions during plasma processing techniques
can influence the properties of a growing film. In this work, we investigated
the effects of controlling ion characteristics (energy, dose) on the
properties of the aforementioned materials during plasma-enhanced
atomic layer deposition (PEALD) on planar and 3D substrate topographies.
We used a 200 mm remote PEALD system equipped with substrate biasing
to control the energy and dose of ions by varying the magnitude and
duration of the applied bias, respectively, during plasma exposure.
Implementing substrate biasing in these forms enhanced PEALD process
capability by providing two additional parameters for tuning a wide
range of material properties. Below the regimes of ion-induced degradation,
enhancing ion energies with substrate biasing during PEALD increased
the refractive index and mass density of TiO<sub><i>x</i></sub> and HfO<sub><i>x</i></sub> and enabled control over
their crystalline properties. PEALD of these oxides with substrate
biasing at 150 °C led to the formation of crystalline material
at the low temperature, which would otherwise yield amorphous films
for deposition without biasing. Enhanced ion energies drastically
reduced the resistivity of conductive TiN<sub><i>x</i></sub> and HfN<sub><i>x</i></sub> films. Furthermore, biasing
during PEALD enabled the residual stress of these materials to be
altered from tensile to compressive. The properties of SiO<sub><i>x</i></sub> were slightly improved whereas those of SiN<sub><i>x</i></sub> were degraded as a function of substrate
biasing. PEALD on 3D trench nanostructures with biasing induced differing
film properties at different regions of the 3D substrate. On the basis
of the results presented herein, prospects afforded by the implementation
of this technique during PEALD, such as enabling new routes for topographically
selective deposition on 3D substrates, are discussed