硅基SiO2平面光波导中硼磷硅玻璃覆盖层的制备和研究

利用等离子体增强化学气相沉积方法．在SiH4／N2O反应气体中掺入PH3和B2H6制备了用于硅基SiO2平面光波导的硼磷硅玻璃覆盖层．分析了磷掺杂和硼掺杂对折射率的影响，提出了选择掺杂气体流量匹配折射率的方法．研究了退火温度和气氛对膜层性能的影响．高温退火使膜层的折射率趋于稳定，对光的吸收损耗减小；采用氧气退火可以抑制和消除氮气退火时膜层中出现的下透明的微晶粒，改善膜层质量．采用多步沉积退火方法，消除了台阶覆盖层出现的空洞和气泡，得到了台阶的覆盖性和覆盖平坦度都较好的硼磷硅玻璃膜层．

PECVD DEPOSITION OF BOROPHOSPHOSILICATE GLASS USED FOR SILICA-BASED PLANAR LIGHTWAVE CIRCUITS

The borophosphosilicate glass(BPSG) layers as the filling coatings to silica-based planar lightwave circuits were obtained by using plasma enhanced chemical vapor deposition with SiH_4/N_2O and PH_3,B_2H_6.The influence of dopants on refractive index of BPSG layers was discussed and the methods related the refractive index of BPSG layers to PH_3 and B_2H_6 gases flows were suggested.The annealing effects of BPSG layers were studied on its optical features and surface map at different annealing conditions.By using multiple deposition followed by annealing,the perfect BPSG layers,which are without void and gap and with fine smoothness,were fabricated.