Monitoring of Condition of Deposited Film Causing Particles in Plasma Etching by Using Practical Load Impedance Monitoring Method

Abstract

We monitor the change in thickness ofˆlms deposited on the inner chamber wall of mass-production plasma etching equipment by using previously developed load impedance monitoring system. Theˆlm composed of etching reaction products causes generation of ‰aked particles and is a factor that decreases production yield and overall equipment eŠectiveness (OEE) in the mass production of LSI. The method that can monitor the change inˆlm thickness and contribute to decreasing ‰aked particles is highly required. The results of this study indicate that mainly the imaginary part of load impedance changes when â lm is deposited on the inner wall, and demonstrate that the system can detect changes in theˆlm thickness without remodeling of the equipment. This real-time and noninvasive monitoring method is expected to improve the production yield and OEE, and it could be used to develop a predictive maintenance regime in future.

Investigation of the relationship between plasma etching characteristics and microstructures of alumina ceramics for chamber parts

“…Particles generated in plasma etching process are one of the most serious problems because they are a main cause of the decrease in the production yield and OEE. [11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27] The chamber parts which are short of useful life also increase the maintenance costs. Therefore, the chamber parts with higher resistance to reactive plasma etching are highly required to reduce corrosion and extend the lifetime of them.…”

Development and evaluation of magnesium oxide-based ceramics for chamber parts in mass-production plasma etching equipment

“…[1][2][3][4][5][6][7][8][9][10] The particles originate from the corrosion of chamber parts and the flaking of films, which are composed of etching reaction products, deposited on the inner walls of the chamber. [1][2][3][4][5][11][12][13][14][15][16] To reduce the corrosion of chamber parts and to extend their lifetime, ceramics with higher resistance to reactive plasma etching than conventional parts are highly required. Yttrium oxide (Y 2 O 3 ) has been used recently because of its higher corrosion resistance than Al 2 O 3 .…”

Easy-to-use detection method for micro-arc discharge in plasma etching equipment by measuring current flowing to ground

“…In the experiments conducted to investigate the validity of the Rogowski coil method, a load impedance monitoring system is used. [18][19][20] The system employs a directional coupler installed between the rf power supply and the matching circuit, and can measure the load impedance, Z L = R L + jX L , from a 50 Ω transmission line, where R L and X L are the real and imaginary parts of the load impedance Z L , respectively, and j is the imaginary unit. In the experiment conducted to detect micro-arc discharge, a conventional loop antenna is used to monitor electromagnetic waves (∼30 MHz) as a reference signal for the occurrence of micro-arc discharge.…”