AVS 46th International Symposium
    Manufacturing Science and Technology Group Wednesday Sessions
       Session MS-WeP

Paper MS-WeP5
Development of New Etching Algorithm for Ultra Large Scale Integrated Circuit and Application of ICP(Inductive Coupled Plasma) Etcher

Wednesday, October 27, 1999, 5:30 pm, Room 4C

Session: Poster Session
Presenter: Y.-C. Lee, Chung-Ang University, Korea
Authors: Y.-C. Lee, Chung-Ang University, Korea
K.-R. Byun, Chung-Ang University, Korea
S.-H. Park, Chung-Ang University, Korea
J.-W. Kang, Chung-Ang University, Korea
E.-S. Kang, Chung-Ang University, Korea
O.-K. Kwon, Chung-Ang University, Korea
H.-J. Hwang, Chung-Ang University, Korea
T.-W. Kim, Chung-Ang University, Korea
Correspondent: Click to Email
We proposed proper etching algorithm for ultra-large scale integrated circuit device and simulated etching process using the proposed algorithm in the case of inductive coupled plasma (ICP) source. Proposed algorithm calculates interactions both in plasma source region and in target material region, and uses binary collision approximation (BCA) method when ion impact on target material surface. Proposed algorithm considers the interaction between source ions in sheath region (from Quartz region to substrate region). After the collision between target and ion, reflected ion collides next projectile ion or sputtered atoms. In ICP etching, because the main mechanism is sputtering, both SiO2 and Si can be etched. Therefore, to obtain etching profiles, mask thickness and mask composition must be considered. Since we consider both SiO2 etching and Si etching, it is possible to predict the thickness of SiO2 for etching of ULSI. In this work, selectivity of Si and SiO2 is more than 50. The distribution of ions is calculated by Monte Carlo method and analytic model (plasma density 1012/cm3, pressures 1∼20mTorr), and the energy (ion flux corresponding to Maxwellian velocity distribution) increases by potential difference in sheath region. Projectile ion moves in time step, has direction and energy. When ion collides targets or ions, direction and energy is changed by impact parameter from binary collision approximation method. Proposed algorithm is efficient for computer calculation and easy to apply other cases. Results of etching simulation using proposed algorithm agree to results of SEM. In conclusion, in the case of ICP type reactor, proposed algorithm is appropriated to obtain etching profiles for ULSI process.