Investigation of SiO2 layers deposited by plasma decomposition of tetra-ethoxy silane in a planar reactor

Abstract

Si02 layers on Si substrates are obtained in planar reactor by decomposition of tetra-ethoxy silane in oxygen plasma. The layers deposited at substrate temperature of 300 "C show some porosity, hygroscopicity, increased etching rate, and water incorporated, so that MOS structures that use such layers have unstable C-U curves and high density of interface states. These characteristics can substantially be improved after annealing a t 400 "C in H,. The etching rate also decreased but reached the value that is characteristic of thermal SiO, only after high temperature annealing.Si02-Schichten auf Si-Substraten werden durch Zersetzung von Tetraethoxysilan im Sauerstoffsplasma eines Planarreaktors erhalten. Die Schichten, die bei einer Substrattemperatur von 300 "C abgeschieden werden, zeigen Porositat, Hygroskopie, erhohte Atzrate und eingeschlossenes Wasser, so de13 MOS Strukturen, die aus diesen Schichten hergestellt werden, unstabile C-U-Kurven und hohe Interface-Zustandsdichten besitzen. Nach Tempern bei 400 "C in H2-Atrnosphare werden diese Charakteristiken wesentlich verbessert. Obwohl sich die Atzrate verringert, erreicht sie den fur thermisches SiO, typischen Wert nur nach einer Hochtemperaturbehandlung.

Low Dielectric Constant Materials

“…[37][38][39] These were replaced by capacitively coupled planar reactors. [40][41][42][43][44][45] When it was discovered that critical deposited film properties (low porosity, increased density, lower water absorption, etc.) were enhanced by ion bombardment (substrate bias), dual-frequency operation was incorporated.…”

“…Although films can be deposited at lower temperatures, temperatures in the range of 350−400 °C usually lead to higher-quality films. Initially capacitively coupled plasmas in Bell jar reactors were utilized. − These were replaced by capacitively coupled planar reactors. − When it was discovered that critical deposited film properties (low porosity, increased density, lower water absorption, etc.) were enhanced by ion bombardment (substrate bias), dual-frequency operation was incorporated.…”