Publications

7 Results

Search results

Jump to search filters

Arbitrary Low-Dimensional Film Transfer Enabled by GeO2 Release Layer

Smyth, Christopher M.; Cain, John M.; Jordan, Matthew; Ivie, Jeffrey A.; Lu, Tzu M.; Chou, Stanley S.

Low-dimensional materials show great promise for enhanced computing and sensing performance in mission-relevant environments. However, integrating low-dimensional materials into conventional electronics remains a challenge. Here, we demonstrate a novel transfer method by which low-dimensional materials and their heterostructures can be transferred onto any arbitrary substrate. Our method relies on a water soluble GeO2 substrate from which lowdimensional materials are transferred without significant perturbation. We apply the method to transfer a working electronic device based on a low-dimensional material. Process developments are achieved to enable the fabrication and transfer of a working electronic device, including the growth of high-k dielectric on GeO2 by atomic layer deposition and inserting an indium diffusion barrier into the device gate stack. This work supports Sandia’s heterogeneous integration strategy to broaden the implementation of low-dimensional films and their devices.

More Details

High kinetic inductance NbTiN superconducting transmission line resonators in the very thin film limit

Applied Physics Letters

Bretz-Sullivan, Terence M.; Lewis, Rupert M.; Lima-Sharma, Ana L.; Lidsky, David A.; Smyth, Christopher M.; Harris, Charles T.; Venuti, Michael; Eley, Serena; Lu, Tzu M.

We examine the DC and radio frequency (RF) response of superconducting transmission line resonators comprised of very thin NbTiN films, < 12 nm in thickness, in the high-temperature limit, where the photon energy is less than the thermal energy. The resonant frequencies of these superconducting resonators show a significant nonlinear response as a function of RF input power, which can approach a frequency shift of Δ f = - 0.15 % in a - 20 dB span in the thinnest film. The strong nonlinear response allows these very thin film resonators to serve as high kinetic inductance parametric amplifiers.

More Details

Thermal activation of low-density Ga implanted in Ge

Applied Physics Letters

Foster, Natalie D.; Miller, Andrew J.; Hutchins-Delgado, Troy A.; Smyth, Christopher M.; Wanke, Michael C.; Lu, Tzu M.; Luhman, Dwight R.

The nuclear spins of low-density implanted Ga atoms in Ge are interesting candidates for solid state-based qubits. To date, activation studies of implanted Ga in Ge have focused on high densities. Here, we extend activation studies into the low-density regime. We use spreading resistance profiling and secondary ion mass spectrometry to derive electrical activation of Ga ions implanted into Ge as a function of the rapid thermal anneal temperature and implant density. We show that for our implant conditions, the activation is best for anneal temperatures between 400 and 650 °C with a maximum activation of 69% at the highest fluence. Below 400 °C, remaining implant damage results in defects that act as superfluous carriers, and above 650 °C, surface roughening and loss of Ga ions are observed. The activation increased monotonically from 10% to 69% as the implant fluence increased from 6 × 10 10 to 6 × 10 12 cm-2. The results provide thermal anneal conditions to be used for initial studies of using low-density Ga atoms in Ge as nuclear spin qubits.

More Details
7 Results
7 Results