AVS 47th International Symposium
    Plasma Science and Technology Wednesday Sessions
       Session PS+MS-WeM

Paper PS+MS-WeM2
Effects of Plasma-induced Charging Damages on Thin Gate Oxide during Plasma Etching Processes

Wednesday, October 4, 2000, 8:40 am, Room 311

Session: Plasma-Induced Damage
Presenter: Y.-K. Kim, Hyundai Electronics Industries Co., Ltd., Korea
Authors: Y.-K. Kim, Hyundai Electronics Industries Co., Ltd., Korea
K.-O. KIm, Hyundai Electronics Industries Co., Ltd., Korea
J.-Y. Kim, Hyundai Electronics Industries Co., Ltd., Korea
C.J. Choi, Hyundai Electronics Industries Co., Ltd., Korea
J.W. Kim, Hyundai Electronics Industries Co., Ltd., Korea
Correspondent: Click to Email
Using the plasma damage monitoring (PDM) system, we investigated the plasma-induced charging damage in the thermally-grown SiO@sub 2@ on p-type Si substrates after plasma etching of gate electrode. Recently, the technique has been frequently employed to monitor oxide damages induced by plasma processes. It determines the changes in oxide electrical properties such as flatband voltage (V@sub fb@), oxide resistivity (@rho@@sub ox@), effective charges (Q@sub eff@), interface trap density (D@sub it@), etc. The measured Q@sub eff@ as well as D@sub it@ value indicates that the plasma has induced a large amount of positive charges trapped in the bulk oxide and the interfacial defects in the SiO@sub 2@-Si interfaces. The trapped oxide charges are also the origin of the large V@sub fb@ shifts as well as the reduced @rho@@sub ox@. The observed charging damages have been found to be dependent strongly on the etching gases as well as the plasma conditions. The site-dependent variations of the charging damages were attributed to the non-uniform radial distribution of the charges on the oxide surfaces during the etching processes. A MOS capacitor was fabricated over the thin thermal oxide by employing the above plasma exposures during the poly-Si electrode and the subsequent pad etching to measure the changes in the gate oxide integrity (GOI) characteristics. Finally, we will quantitatively show that the leakage current of the thin gate oxide after the plasma processing is strongly related with the measured PDM results.