Me Merijn Donders

Remote Plasma ALD of Platinum and Platinum Oxide Films

Platinum and platinum oxide films were deposited by remote plasma atomic layer deposition (ALD) from the combination of (methylcyclopentadienyl)trimethylplatinum (MeCpPtMe 3 ) precursor and O 2 plasma. A short O 2 plasma exposure (0.5 s) resulted in low resistivity (15 μΩ cm), high density (21 g/cm 3 ), cubic Pt films, whereas a longer O 2 plasma exposure (5 s) resulted in semiconductive PtO 2 films. In situ spectroscopic ellipsometry studies revealed no significant nucleation delay, different from the thermal ALD process with O 2 gas which was used as a benchmark. A broad temperature window (100―300°C) for remote plasma ALD of Pt and PtO 2 was demonstrated.

Atomic layer deposition for nanostructured Li-ion batteries

Nanostructuring is targeted as a solution to achieve the improvements required for implementing Li-ion batteries in a wide range of applications. These applications range in size from electrical vehicles down to microsystems. Atomic layer deposition (ALD) could be an enabling technology for nanostructured Li-ion batteries as it is capable of depositing ultrathin films (1–100 nm) in complex structures with precise growth control. The potential of ALD is reviewed for three battery concepts that can be distinguished, i.e., particle-based electrodes, 3D-structured electrodes, and 3D all-solid-state microbatteries. It is discussed that a large range of materials can be deposited by ALD and recent demonstrations of battery improvements by ALD are used to exemplify its large potential.

Remote Plasma Atomic Layer Deposition of Co3O4 Thin Films

Cobalt oxide thin films have been deposited with remote plasma atomic layer deposition (ALD) within a wide temperature window (100-400 degrees C), using CoCp2 as a cobalt precursor and with remote O-2 plasma as the oxidant source. The growth rate was 0.05 nm/cycle and both the precursor dosing and plasma exposure exhibit saturation after 2 s, all independent of the substrate temperature. This novel combination resulted in the deposition of high density (similar to 5.8 g/cm(3)), stoichiometric Co3O4 showing a preferential (111) orientation for all temperatures. X-ray diffraction, spectroscopic ellipsometry, and Fourier transform infrared spectroscopy independently indicate an increasing crystallinity with increasing substrate temperature, whereas the surface roughness remains low (

Atomic layer deposition for all-solid-state 3D-integrated batteries

All-solid-state 3D integrated batteries can reach the energy storage capacity required for future wireless devices by exploiting the third dimension. Conformal deposition techniques such as atomic layer deposition (ALD) are needed to deposit the battery materials. In this work, the current development of ALD processes for 3D integrated batteries is reviewed. We have developed both the TiN diffusion barrier and Pt cathode current collector processes. TiN showed good barrier properties in 3D, although a higher than expected charge density was observed, which could be attributed to a lower thickness and/or different material properties at the bottom of the 3D structures. The remote plasma ALD process for Pt showed fast growth initiation and good adhesion of the films. Furthermore, sufficient step coverage for the battery application was found. ALD is also potentially able to deposit the active battery layers, although the deposition of Li-containing materials is expected to be challenging. ©2009 COPYRIGHT ECS - The Electrochemical Society

Remote Plasma Atomic Layer Deposition of Thin Films of Electrochemically Active LiCoO2

One of the remaining challenges in the field of portable electronics is the miniaturization of lithium-ion batteries without decreasing their storage capacity. To tackle this challenge and to effectively integrate battery technology in even a wider variety of applications, it is essential to produce high quality thin films for all-solid-state batteries. A remote plasma ALD process for the positive electrode material LiCoO2 was developed using the combination of CoCp2 as the cobalt precursor, LiOtBu as the lithium precursor and O2 plasma as the oxidant source. The thin films were deposited at a temperature of 325 °C with a virtually linear growth rate of 0.06 nm/cycle. After annealing the samples at 700 °C for 6 minutes the high temperature phase LiCoO2 was obtained, as demonstrated by XRD and Raman spectroscopy measurements. Electrochemical charge/discharge cycling showed good electrochemical activity with a promising storage capacity.

Remote Plasma and Thermal ALD of Platinum and Platinum Oxide Films

Platinum and platinum oxide films were deposited using thermal and remote plasma ALD. The combination of MeCpPtMe3 precursor and O2 gas or a short (0.5 s) O2 plasma exposure resulted in high purity, low-resistivity (15 microOhm cm), high-density (21 g/cm3), cubic platinum films. The combination of MeCpPtMe3 precursor with a longer (5 s) O2 plasma exposure resulted in semi-conductive PtO2 films with a band gap of ~1.5 eV. The long nucleation delay observed with the thermal process could be overcome by using the remote plasma process where atomic oxygen is provided from the gas phase. The ALD process dependence on substrate temperature was investigated, where both the thermal and the remote plasma Pt process revealed a temperature window from 200 C to 300 C and the remote plasma PtO2 process had a temperature window from 100 C to 300 C.

Towards High Energy Density 3D-integrated Lithium-ion Micro-batteries

To investigate the feasibility of a 3D integrated all-solid-state micro-battery, the deposition of several battery materials was investigated. Deposition techniques where used that are in principle able to deposit step conformally in 3D structures: ALD was used to create a conductive Pt current collector, and LPCVD was applied for the deposition of poly-silicon anodes and LiCoO2 cathodes. The layers, initially deposited on planar substrates, showed the expected physical and electrochemical behavior and are in principle suitable for solid state micro-batteries.