摩擦化学反应活化能对CMP的影响

Effect of Friction Chemical Reaction Activation Energy on CMP Process

根据质量作用定律,测定了铜膜在静态腐蚀和化学机械抛光(Chemical Mechanical Polishing,CMP)两种反应条件下的化学反应速率常数;通过Arrhenius方程,测定了铜膜在两种反应条件下的化学反应活化能.结果表明:当抛光液温度为298.15K,工作压力为13 780Pa时,静态腐蚀条件下体系化学反应速率常数是114.80s^(-1),而CMP条件下体系的化学反应速率常数是412.11s^(-1),同时,CMP条件下的反应活化能为4 849.80J,静态腐蚀条件下的反应活化能为31 870.30J,由此得出,反应活化能的降低是CMP过程中的机械摩擦作用所致.因此,根据CMP过程中铜膜和抛光垫各自克服滑动摩擦力所作的系统功,推导出CMP过程中活化能降低值的系统功表达式,并通过改变工作压力和转速来验证该表达式的适用性.

According to the law of mass action,the reaction rate constants of copper film chemical reaction are measured under static corrosion and dynamic chemical mechanical polishing(CMP)process.The activation energy of copper film chemical reaction is acquired under the two kinds of reaction conditions above mentioned based on the Arrhenius equation.The results show that:as the slurry temperature is 298.15 K with working pressure 13 780 Pa during the CMP process,and the chemicalreaction rate constant of the system under the static corrosion condition is 114.80 s^(-1),and the reaction activation energy is 31 870.30 J,while the reaction rate constant increases to 412.11 s^(-1) and reaction activation energy decreases to 4 849.80 J under the CMP condition.Thus,the mechanical friction effect in the CMP process causes the decline of activation energy as a result.Therefore,according to the system power produced by the sliding friction between the copper film and the polishing pad in the CMP process,system power expression used for describing the decline of activation energy in the CMP process is calculated.And also the applicability of the expression has been verified by changing the work pressure and speed of the CMP process.