Sidewall Slope Control of InP Via Holes for 3D Integration.

This is the first demonstration of sidewall slope control of InP via holes with an etch depth of more than 10 µm for 3D integration. The process for the InP via holes utilizes a common SiO2 layer as an InP etch mask and conventional inductively coupled plasma (ICP) etcher operated at room temperature and simple gas mixtures of Cl2/Ar for InP dry etch. Sidewall slope of InP via holes is controlled within the range of 80 to 90 degrees by changing the ICP power in the ICP etcher and adopting a dry-etched SiO2 layer with a sidewall slope of 70 degrees. Furthermore, the sidewall slope control of the InP via holes in a wide range of 36 to 69 degrees is possible by changing the RF power in the etcher and introducing a wet-etched SiO2 layer with a small sidewall slope of 2 degrees; this wide slope control is due to the change of InP-to-SiO2 selectivity with RF power.

In-vivo measurements of the dielectric properties of breast carcinoma xenografted on nude mice.

A developing method of cancer detection is to use electromagnetic waves to compare the dielectric properties of normal and cancerous tissue. Because most of the previous studies consisted of dielectric measurements taken ex-vivo, this study investigated the advantages of in-vivo measurements, obtained using the newly developed insertion-type planar probe, through the measurements of cancer (MDA MB 231), which was cultivated and implanted into the mammary fat pad of nude mice. Reflection coefficients were obtained in the broadband frequency range from 0.5 to 30 GHz, from which broadband complex permittivity data was extracted. Complex permittivity, in addition to other parameters such as conductivity and characteristic frequency, were used to make comparisons between cancerous tissue, normal muscle tissue and fat tissue, as well as comparisons between in-vivo and ex-vivo measurements. This study investigated the suitability of in-vivo cancer detection using microwaves with the newly developed insertion-type planar probe. Results showed that both sensitivity and specificity of the current method was 97%. In addition, predictive values were 99% for the positive and 94% for the negative, thus greatly enhancing the practicality of this method. In conclusion, it was demonstrated that in-vivo measurements are highly beneficial in studying the potential of microwaves as a diagnostic tool of breast cancer, especially in combination with the newly developed insertion-type planar probe.