Effects of dc bias on the kinetics and electrical properties of silicon dioxide grown in an electron cyclotron resonance plasma

Abstract

Thin (3-300 nm) oxides were grown on single crystal silicon substrates at temperatures from 523 K to 673 K in a low pressure electron cyclotron resonance oxygen plasma. Oxides were grown under floating, anodic or cathodic bias conditions, although only the oxides grown under floating or anodic bias conditions are acceptable for use as gate dielectrics in metal-oxide-semiconductor (MOS) technology. Oxide thickness uniformity as measured by ellipsometry decreased with increasing oxidation time for all bias conditions. Oxidation kinetics under anodic conditions can be explained by negatively charged atomic oxygen, O", transport limited growth. Constant current anodizations yielded three regions ofgrowth: 1) a concentration gradient dominated regime for oxides thinner than 10 nm; 2) a field dominated regime with ohmic charged oxidant transport for oxide thickness inthe range of10 nm to approximately 100 nm; and 3)a space-charge limited regime for films thicker than approximately 100 nm. The relationship between oxide thickness (x^), overall potential drop (Vâ nd ion current (jj) in the space-charge limited transport region was of the form: yx a V^/ x^.

Particle in Cell Simulation of Low Temperature Laboratory Plasmas

“…Discharges in Oxygen are of vital importance for a large variety of etching and thin film deposition techniques [23][24][25][26][27][28][29]. Similar to other reactive molecular gases with internal degrees of freedom, O ¾ has a quite complicated plasma-chemistry which, so far, has been analyzed primarily within global models [30][31][32].…”

Radio-frequency discharges in oxygen: I. Particle-based modelling

“…Most notably O 2 , either as the main feedstock gas or as an admixture to halogen-or silicon-based gases, is of vital importance for a large variety of etching and thin-film deposition techniques [1,2,3,4,5,6,7]. The requirements on the controllability and predictability of these processes are so high that further advancement of this technology will depend on modeling tools which go beyond the macroscopic, fluid-type approximations, which, for instance, cannot reliably predict the velocity distributions of the species.…”

Growth and properties of fluorinated plasma oxide for Si MOSFET devices

“…The breakdown strength of the oxide is defined in the conventional way for MOSFET devices [7], namely the electric field at which the current through the oxide is 1 lA/cm 2 . The breakdown field for the oxide grown using oxygen alone was in the range of 8-11 MV/cm, an acceptable range for MOSFET devices.…”

“…Such techniques lead to excessive hydrogen concentration in the oxides, which leads to instability upon stressing. To overcome such effects, plasma oxidation of Si in an oxygen plasma has been utilized in the past [2][3][4][5][6][7][8][9]. Various types of plasma rectors have been used, including microwave plasma, ECR plasma and standard diode plasma.…”