Wafer Bonding of SiC-AlN at Room Temperature for All-SiC Capacitive Pressure Sensor.

Wafer bonding of a silicon carbide (SiC) diaphragm to a patterned SiC substrate coated with aluminum nitride (AlN) film as an insulating layer is a promising choice to fabricate an all-SiC capacitive pressure sensor. To demonstrate the bonding feasibility, a crystalline AlN film with a root-mean-square (RMS) surface roughness less than ~0.70 nm was deposited on a SiC wafer by a pulsed direct current magnetron sputtering method. Room temperature wafer bonding of SiC-AlN by two surface activated bonding (SAB) methods (standard SAB and modified SAB with Si nano-layer sputtering deposition) was studied. Standard SAB failed in the bonding, while the modified SAB achieved the bonding with a bonding energy of ~1.6 J/m2. Both the microstructure and composition of the interface were investigated to understand the bonding mechanisms. Additionally, the surface analyses were employed to confirm the interface investigation. Clear oxidation of the AlN film was found, which is assumed to be the failure reason of direct bonding by standard SAB.

High Thermal Boundary Conductance across Bonded Heterogeneous GaN-SiC Interfaces.

High-power GaN-based electronics are limited by high channel temperatures induced by self-heating, which degrades device performance and reliability. Increasing the thermal boundary conductance (TBC) between GaN and SiC will aid in the heat dissipation of GaN-on-SiC devices by taking advantage of the high thermal conductivity of SiC substrates. For the typical growth method, there are issues concerning the transition layer at the interface and low-quality GaN adjacent to the interface, which impedes heat flow. In this work, a room-temperature bonding method is used to bond high-quality GaN to SiC directly, which allows for the direct integration of high-quality GaN with SiC to create a high TBC interface. Time-domain thermoreflectance is used to measure the GaN thermal conductivity and GaN-SiC TBC. The measured GaN thermal conductivity is larger than that of grown GaN-on-SiC by molecular beam epitaxy. High TBC is observed for the bonded GaN-SiC interfaces, especially for the annealed interface (∼230 MW m-2 K-1, close to the highest value ever reported). Thus, this work provides the benefit of both a high TBC and higher GaN thermal conductivity, which will impact the GaN-device integration with substrates in which thermal dissipation always plays an important role. Additionally, simultaneous thermal and structural characterizations of heterogeneous bonded interfaces are performed to understand the structure-thermal property relation across this new type of interface.

Patient consent to publication and data sharing in industry and NIH-funded clinical trials.

BACKGROUND: Participants are recruited into clinical trials under the assumption that the research will contribute to medical knowledge. Therefore, non-publication trials-and, more recently, lack of data sharing-are widely considered to violate the trust of trial participants. Existing practices regarding patient consent to publication and data sharing have not been evaluated. Analyzing informed consent forms (ICFs), we studied what trial participants were told regarding investigators' intention to contribute to medical knowledge, publish trial results, and share de-identified trial data. METHODS: We obtained 98 ICFs of industry-funded pre-marketing trials for all (17) antibiotics approved by the European Medicines Agency and 46 ICFs of publicly funded trials from the National Heart, Lung and Blood Institute Biologic Specimen and Data Repository Information Coordinating Center (BioLINCC) data repository. Three authors independently reviewed ICFs to identify and extract what was stated or implied regarding: (1) publication of results; (2) sharing de-identified data; (3) data ownership; (4) confidentiality of identifiable data; and (5) whether the trial will produce knowledge that offers public benefit. Consensus was obtained from the two reviewers with the greatest overall agreement on all five measures. Disagreements were resolved through discussion among all authors. RESULTS: Four (3%) trials indicated a commitment to publish trial results; 140 (97%) did not commit to publishing trial results; six (4%) indicated a commitment to share de-identified data with third party researchers. Commitments to share were more common in publicly funded trials than industry-funded trials (7% vs 3%). A total of 103 (72%) ICFs indicated the trials will or may produce knowledge that offers public benefits, while 131 (91%) ICFs left unstated who "owned" trial data; of those with statements, the sponsor always claimed ownership. Patient confidentiality was guaranteed in 137 (95%) trials. CONCLUSIONS: Our results suggest that consent forms rarely disclose investigators' intentions regarding the sharing of de-identified data or publication of trial results.