Crystalline characteristics of annealed AlN films by pulsed laser treatment for solidly mounted resonator applications

AlN films were deposited on Si substrates using a reactive RF magnetron sputtering process and then the films were annealed by using different laser powers and wavelengths (355 nm, 532 nm and 1064 nm). For all three laser systems, the (002) peak intensity was obviously improved following laser irradiation. The improvement in the crystalline property was particularly obtained in the AlN film processed at 355 nm. In particular, given the use of the optimal laser power (0.025 W), the (002) peak intensity was 58.7% higher than that of the as-deposited film. The resonant frequency and 3 dB bandwidth of a SMR filter with an unprocessed AlN film were found to be 2850 MHz and 227.81 MHz, respectively. Following laser treatment with a wavelength of 1064 nm and a power of 0.25 W, the resonant frequency changed from 2850 to 2858 MHz. Moreover, 3 dB bandwidth changed from 227.81 to 202.49 MHz and the return loss of the filter reduced from 17.28 to 16.48 dB. Overall, the results thus show that the frequency response of the SMR filter can be adjusted and the return loss reduced by means of laser treatment with an appropriate wavelength.

Genetic Modifiers of Progression-Free Survival in Never-Smoking Lung Adenocarcinoma Patients Treated with First-Line Tyrosine Kinase Inhibitors

RATIONALE

Patients with non-small cell lung cancer (NSCLC) with mutated epidermal growth factor receptor (EGFR) are relatively sensitive to EGFR-tyrosine kinase inhibitor (TKI) treatment and have longer progression-free survival (PFS) when treated with EGFR-TKI compared with platinum-based chemotherapy. However, many patients with advanced NSCLC who have mutated EGFR do not respond to first-line EGFR-TKI treatment and still have shorter PFS.

OBJECTIVES

The aim of this study was to identify genetic variants associated with PFS among patients with lung adenocarcinoma who were treated with first-line EGFR-TKIs.

METHODS

A genome-wide association study on PFS was performed in never-smoking women diagnosed with lung adenocarcinoma and who were treated with first-line EGFR-TKIs (n = 128). Significant single-nucleotide polymorphisms (SNPs) were selected for follow-up association analysis (n = 198) and for replication assay in another independent cohort (n = 153).

MEASUREMENTS AND MAIN RESULTS

We identified SNPs at 4q12 associated with PFS at genome-wide significance (P < 10^-8) and with an estimated hazard ratio of more than 4. This association was also replicated in a larger but similar cohort and in an independent NSCLC cohort. Follow-up functional analyses showed that these SNPs were associated with the expression of EGFR, which encodes the TKI target, and with a nearby gene neuromedin-U, which encodes a G protein-coupled receptor ligand known to be involved in the progression of NSCLC. Considering these as possible prognostic biomarkers for the treatment of patients with late-stage lung cancer, we found that these SNPs were not associated with EGFR mutation status or with polymorphism of the Bcl2-interacting mediator of cell death gene.

CONCLUSIONS

Genetic variants in 4q12 merit further investigation to assess their potential as pharmacogenomic predictors for and to understand the biology underlying its influence on PFS in patients treated with TKI therapy.

Theoretical investigation of the SAW properties of ferroelectric film composite structures

The characteristics of surface acoustic waves (SAW) propagating on a three-layered structure consisting of a perovskite-type ferroelectric film, a buffer layer and a semiconductor substrate have been studied theoretically. Large coupling coefficients (K(2)) can be obtained when the interdigital transducer (IDT) is on top of the perovskite-type ferroelectric film, with (type 4) and without (type 3) the floating-plane electrode at the perovskite-type ferroelectric film-buffer layer interface. In the above cases, the peak values of K (2) Of the Pb(Zr,Ti)O(3) (PZT) films (3.2%-3.8%) are higher than those of the BaTiO(3) (BT) and PbTiO(3) (PT) films. In the IDT configuration of type 4, there exists a minor peak of the coupling coefficients for the PZT and BT films, but not for the PT films when the normalized thickness (hK) of the perovskite-type ferroelectric film is about 0.3. The minor peak values of the coupling coefficients (0.62%-0.93%) for different layered structures (PZT/STO/Si, PZT/MgO/Si, and PZT/MgO/GaAs) all decrease when we increase hK value from 0 to 0.25. The results could be useful in the integration of ferroelectric devices, semiconductor devices, and SAW devices on the same substrate.

The effect of an SiO(2) buffer layer on the SAW properties of ZnO/SiO(2)/GaAs structure

The effect of an SiO(2) buffer layer on the surface acoustic wave (SAW) properties of ZnO/SiO(2)/GaAs structure is examined. Both theoretical and experimental results show that the coupling coefficient is increased appreciably by providing an SiO(2 ) film between the ZnO film and the GaAs substrate. Adding an SiO (2) film is also beneficial to the promotion of quality of ZnO thin film. The results could be useful for the further development of monolithic SAW devices.