The Study of Ashing Properties on Photoresist in Four Mask Process Based on Oxide Active Layer

In this paper, we study the effect of enhanced inductively coupled plasma dry etching equipment(planer inductively coupled plasma, PICP) on the ashing properties of photoresist in a four mask process based on Oxide technology.The influence of oxygen flow, power, pressure on ashing rate, uniformity, critical dimension loss(CD loss),and vertical loss of photoresist was evaluated via the orthogonal experiment.The experimental results show that the oxygen flow and power have a significant effect on vertical loss and CD loss, respectively.When the oxygen flow is 6000 mL/min, the vertical loss reaches the maximum; when the power is 32 kW,the CD loss reaches the minimum.Besides, when the chamber pressure and the ashing time are 1.3 Pa and 40 s, the CD loss and the vertical loss are 1.36 μm and 0.84 μm, and the value of CD loss/vertical loss is optimal.