Enrica Ravizza

Post CMP Wet Cleaning Influence on Cu Hillocks

Up to date, it is commonly reported in literature that the amount of copper hillocks is dependent on a) the total amount of residual Cu oxide after Cu CMP, and b) the Cu nitridation. The present work describes how that is only partially true: hillocks depend also on the kind of oxide and on the roughness of the surface after wet treatment. This contribution is even more important than what reported in literature. A tentative model for this behavior is proposed.

Study of TiW Conditioning through Different Wet and Dry Treatments to Promote Ni Electroless Growth

Electroless Ni deposition is often used in presence of Cu, Ti and Au. Recently TiW has also started to be employed, but with this alloy the Ni deposition is not always neat. In our work we investigate the effect of different wet treatments on the Ni growth by means of XPS analyses and SEM inspections. It is found that an oxidized surface inhibits the activator deposition. The de-oxidized Ti atoms in TiW on the other hand are believed to act as the principal sites for Pd seed deposition and subsequent Ni growth.

Adhesion Improvement through Plasma Surface Treatments on Palladium Surface

Introduction As a surface finishing, the electroless nickel / electroless palladium (ENEP) has received increased attention because of its lower cost respect to the electroless nickel / electroless palladium / immersion gold (ENEPIG). Both ENEP and ENEPIG approaches are compatible with copper wire bonding, further reducing the manufacturing cost [1]. In this matter a major challenge is to achieve a good adhesion between noble metals (e.g. palladium or gold) used for pad finishing and the final insulating and passivation layer (e.g. polyimide). Most passivation materials have high permeability to air and moisture, suggesting that a passivation treatment of the noble metal surface could be needed. Different plasma treatments have been considered with the objectives of getting cleaner and less moisture sensitive surface, avoiding detachment of the passivation layer from the palladium surface (Fig. 1). Both reducing and oxidizing plasma treatments have been tested on palladium surface, focusing also on the effect of temperature.

Impact of Surface Treatment of Si3N4 on Subsequent SiO2 Deposition

In a typical Power Device on the 0.16μm node, the isolation module is one of the most critical steps. The trench to be filled in those devices is rather deep and needs a considerable amount of a suitable dielectric material. The choice of dielectric in the present paper is falling on the SubAtmosphericUndopedSilicaGlass (SAUSG oxide) [1].

Evaluation of HfLaOx as Blocking Layer for Innovative Nonvolatile Memory Applications

In this paper, a study of a La-based high-k oxide to be employed as blocking oxide in future non-volatile scaled memory devices is presented. Hf1-xLaxOy deposited by atomic layer deposition is considered. In order to allow the integration of this material, its chemical interaction with an Al2O3 cap layer has been studied. Moreover, the electrical characteristics have been evaluated after integration in capacitor structures. The rare earth-based ternary oxide presents promising characteristics to be a good candidate as active dielectric for non volatile memory devices.