为了实现在8寸化学机械抛光设备上进行小尺寸镀铜InP晶圆的减薄抛光工作，提高设备的兼容性，缩减工艺步骤，减少过多操作导致InP晶圆出现裂纹暗伤和表面颗粒增加等问题，自制特殊模具，使小尺寸InP晶圆在8寸化学机械抛光设备上进行加工，再根据InP晶圆易碎的缺陷问题，通过调整设备的抛光头压力、转速和抛光垫的转速等相关工艺参数，使其满足后续键合工艺的相关需求。实验结果表明：在使用特殊模具下，当抛光头的压力调整为20.684 kPa、抛光头与抛光垫的转速分别为：93 r/min和87 r/min时，InP晶圆的表面粗糙度达到：R_a≤1 nm；表面铜层的去除速率达到3 857×10^-10/min；后续与8寸晶圆的键合避免键合位置出现空洞等缺陷，实现2寸InP晶圆在8寸设备上的CMP工艺，大大降低了CMP工艺成本，同时避免晶圆在转移过程中出现表面颗粒度增加和划伤的情况，实现了InP晶圆与Si晶圆的异质键合及Cu互连工艺。

熔盐堆核燃料后处理过程中分离去除裂变产物，回收载体熔盐，既可减少废物量，又有利于实现有用物质的循环利用。采用水合硫化钠（Na₂S?5H₂O）作为沉淀剂，研究了LiF-BeF₂熔体中研究了氟化稀土（Ce、Nd、Sm、Eu、Y、Yb）以及氟化钍的高温沉淀反应，比较了不同条件下稀土的去除率。研究表明：600 °C、稀土与沉淀剂的比例为1∶2时，稀土的去除率均低于90%。为进一步提高去除率，采用沉淀-蒸馏联合的方法，沉淀后的混合盐继续升温至950 °C，压力10 Pa的真空条件下蒸馏20 min，冷凝收集盐中稀土Nd的含量降低至1.39×10^-4 g?g^-1，Nd的去除率提高至99.6%，同时氧、硫的含量分别为8.5×10^-5 g?g^-1、1.50×10^-4 g?g^-1。进一步利用X射线衍射（X-ray Diffraction，XRD）、X射线光电子能谱（X-ray Photoelectron Spectroscopy，XPS）、能量色谱仪（Energy Dispersive Spectrometer，EDS）等手段分析沉淀物的组成，确定沉淀物主要为稀土硫化物及稀土硫氧化物。研究表明，硫化物沉淀法从废熔盐中分离稀土具有可行性，采用沉淀-蒸馏联合处理获得稀土99%以上的分离效率，这为纯化废盐、实现熔盐的重复利用提供参考。

On-chip stimulated Brillouin scattering (SBS) has attracted extensive attention by introducing acousto-optic coupling interactions in all-optical signal processing systems. A series of chip-level applications such as Brillouin lasers, amplifiers, gyroscopes, filters, and nonreciprocal devices are realized based on Brillouin acousto-optic interaction. Here, we first introduce the fundamental principle of SBS in integrated photonics and a method for calculating Brillouin gain; then we illustrate the Brillouin effect on different material platforms with diverse applications. Finally, we make a concise conclusion and offer prospects on the future developments of on-chip SBS.

Abstract

We report holographic fabrication of nanoporous distributed Bragg reflector (DBR) films with periodic nanoscale porosity via a single-prism conuration. The nanoporous DBR films result from the phase separation in a material recipe, which consists of a polymerizable acrylate monomer and nonreactive volatile solvent. By changing the interfering angle of two laser beams, we achieve the nanoporous DBR films with highly reflective red, green, and blue colors. The reflection band of the nanoporous DBR films can be tuned by further filling different liquids into the pores inside the films, resulting in the color change accordingly. Experimental results show that such kinds of nanoporous DBR films could be potentially useful for many applications, such as color filters and refractive index sensors.