AVS 58th Annual International Symposium and Exhibition
    Plasma Science and Technology Division Monday Sessions
       Session PS+SE-MoA

Paper PS+SE-MoA1
Mechanical Analysis of the Line Edge Roughness in the sub-20nm Line Patterns

Monday, October 31, 2011, 2:00 pm, Room 201

Session: Advanced FEOL / Gate Etching II
Presenter: SangWuk Park, Samsung Electronics Co., Ltd, Republic of Korea
Authors: S.W. Park, Samsung Electronics Co., Ltd, Republic of Korea
K.H. Baek, Samsung Electronics Co., Ltd, Republic of Korea
S.H. Choi, Lam Research Corporation
J.S. Hong, Lam Research Corporation
K.S. Shin, Samsung Electronics Co., Ltd, Republic of Korea
Y.G. Shin, Samsung Electronics Co., Ltd, Republic of Korea
H.G. Kang, Samsung Electronics Co., Ltd, Republic of Korea
Correspondent: Click to Email
In this study, the deterioration of line edge roughness during plasma etching process was analyzed to find possible control parameters. According to the aggressive design rule shrinkage of memory devices, the physical width of line patterns has become around 20nm. Controlling line edge and width roughness now became one of the biggest challenges in patterning process. Though a number of studies on this matter have done, the wiggling of line patterns is still making the migration slower. It is well know truth that the line edge and width roughness are mainly caused by the projection of poor photoresist patterns. However, the recent line patterns of around 20nm design rules experience severe wiggling added from the plasma etching process. This study focused on this etch-induced deformation that increased line edge roughness from the prior status. The final line edge roughness was assumed as the sum of the wiggling projected from that of mask pattern and the deformation during plasma process. The deformation part was explained with the equations of the mechanical beam theory assuming several stress sources originated from the plasma. This newly introduced approach could suggest the direction of process modification for more robust profile against deformation. Moreover, combining with the material properties of commonly used materials, this approach could estimate the extent of lateral deformation so that the ultimate size of line patterns could be expected in the aspect of line edge roughness.