静电夹取方法和装置;ELECTROSTATIC CLAMPING METHOD AND APPARATUS

摘要

描述一种在电浆处理期间，以静电方式将介电质晶圆(30)夹取至处理工作台(3)之方法。工作台(3)中嵌埋有指叉式电极(26,28)。本方法包含将相反之第一与第二极性之各别电压施加至相邻电极(26,28)，其中系在晶圆(30)中诱发极性与各别下层电极相反之极化电荷，藉此以静电方式将晶圆夹取至工作台；并且，在一预定时间(ton)之后，令电压之极性反向，以致极化电荷及静电夹取延续。各该第一与第二极性的该供电时间(ton)系预选为;a)大于在该晶圆中产生充分极化电荷的所需时间(T1)，使得该晶圆系在撤回夹取电压之后，以所需压力持固至少2秒，b)在稳态电压及电浆下，小于用以令该晶圆与该工作台分离第一预定量之时间(T2)，以及c)在外施电压施加完成后，于没有电浆的情况下，小于令该晶圆与该基材分离第二预定量之时间(T3)。;该第一与第二极性之间的切换时间(ts)小于该时间(T1)并小于2秒。; and, after a predetermined time (ton), reversing the polarities of the voltages so that the polarisation charges and electrostatic clamping continues. The on time (ton) of each of the first and second polarities is preselected to be a) greater than the time (T1) required to generate sufficient polarisation charge in the wafer such that the wafer is held with a required pressure for at least 2 seconds after withdrawing of clamping voltages, b) less than the time (T2) for the wafer to separate from the table by a first predetermined amount while in the presence of a steady voltage and a plasma, and c) less than the time (T3) for the wafer to separate from the substrate by a second predetermined amount in the absence of a plasma, after an applied voltage has been applied. ;The time (ts) for switching between the first and second polarities is less than the time (T1)and less than 2 seconds.