紫外光和催化剂对GaN电化学特性及CMP速率的影响

Effects of UV Light and Catalyst on Electrochemical Properties and Chemical Mechanical Polishing Rate of GaN

通过电化学和化学机械抛光(CMP)实验研究了紫外光及催化剂对GaN电化学特性及去除速率的影响。电化学实验结果表明,采用K2S2O8作为氧化剂时GaN的腐蚀电位随氧化剂的浓度增大而降低。在H2O2和K2S2O8体系中分别加入ZnO催化剂并进行紫外光照射,其腐蚀电位进一步降低,腐蚀速率加快。CMP结果显示,在H2O2和K2S2O8抛光液体系中,紫外光的加入能有效提高GaN的去除速率;加入ZnO催化剂后,GaN的去除速率进一步提高,当H2O2体积分数为3%、 ZnO的质量分数为0.05%时,GaN的去除速率达239.7 nm/h;当K2S2O8体积分数0.15 mol/L、ZnO的质量分数0.05%时,GaN的去除速率为428.0 nm/h,此时GaN表面粗糙度为1.18 nm。紫外光照射和ZnO催化剂能够明显提高CMP过程中GaN的去除速率。

The effects of ultraviolet irradiation and catalyst on the electrochemical properties and removal rate of GaN were investigated by electrochemical and chemical mechanical polishing(CMP)expe-riments.The results of electrochemical experiments show that the corrosion potential of GaN decreases with the increase of the oxidant concentration when K2S2O8 is used as an oxidant.When the ZnO catalyst is added to the H2O2 and K2S2O8 systems and irradiated by ultraviolet light,the corrosion potential is further reduced and the corrosion rate is accelerated.The results show that the removal rate of GaN can be effectively improved by the addition of ultraviolet irradiation during CMP using the H2O2 and K2S2O8 po-lishing solution system,and the removal rate of GaN is further improved after the addition of ZnO catalyst in the polishing solution.When the volume fraction of H2O2 is 3%and the mass fraction of ZnO is 0.05%,the removal rate of GaN is 239.7 nm/h.When the volume fraction of K2S2O8 is 0.15 mol/L and the mass fraction of ZnO is 0.05%,the removal rate of GaN is 428.0 nm/h.At this time,the GaN surface roughness is 1.18 nm.The removal rate of GaN can be increased significantly by ultraviolet irradiation and ZnO catalysts during CMP.