Michael D. Armacost

Big Data Capabilities Applied to Semiconductor Manufacturing Advanced Process Control

As requirements on data volumes, rates, quality, merging, and analytics increase exponentially in the digital universe, semiconductor manufacturers are faced with a need for new approaches to data management and use across the Fab. These are often termed “big data” challenges. In our industry big data solutions will be key to scaling advanced process control (APC) solutions to finer levels of control and diagnostics. However the main impact will be to better enable more effective predictive technologies such as predictive maintenance (PdM), virtual metrology and yield prediction, all of which utilize data from traditional APC capabilities that include fault detection and classification and run-to-run control. PdM represents one area where big data solutions are generating significant benefits across a variety of process types. Moving to big data solutions involves addressing the aforementioned requirements either with enhancements of existing systems or moving to more big data friendly platforms. Big data friendly platforms applied to APC systems provide quantifiable cost-of-ownership and speed improvements, thereby better enabling high quality prediction solutions. Initially, big data solutions will largely be delegated to off-line and on-time critical tasks; over the longer term these big data solutions will increasingly be leveraged for time critical and real-time capabilities.

Minimization of plasma ashing damage to OSG low-k dielectrics

This paper investigated the plasma ashing damage to patterned porous low k structures with the objective to minimize the plasma damage by optimizing the low-k structural geometry and plasma chemistry. We first extended the plasma altered layer model to formulate the transport kinetics of the plasma process in patterned low-k structures. This enabled us to analyze the effects of the hardmask thickness, trench width and trench length on the plasma interaction with the trench sidewall. Then CO/O2 and CO2/N2 plasmas were used to replace O2 plasma for ashing process to examine their potential for reducing plasma ashing damage to porous low k patterned structures. With increasing CO in CO/O2 plasma, the extent of plasma induced damages was found to decrease. Similarly, with increasing N2 in CO2/N2 plasma, the plasma induced damages were also found to decrease. On the basis of the Knudsen diffusivity difference among C, N, and O, the reduction of plasma induced damage was ascribed to the formation of C- and N- rich passivation layer on the sidewall and pore surface of the patterned low-k structure.

Plasma altered layer model for plasma damage characterization of porous OSG films

A plasma altered layer model was developed to characterize plasma damage in porous OSG (organosilicate glass) low-k dielectrics by taking into account the kinetics of radical diffusion, reaction, and recombination. A gap structure was designed to study plasma damage and validate the model. It consisted of two parallel rectangular Si spacers and a top optical mask to control the energy and intensity of ion, photon, and radical in the plasma. CO2 and O2 plasma-induced damages were found to depend on the radical concentration, the energy and intensity of VUV photons, the ion energy, and the substrate temperature. Overall, the results obtained from plasma damage studies were consistent with the prediction of the model. The application of the model was demonstrated in a study of He plasma pretreatment and damage formation in OSG films with varying carbon concentrations. Both treatments were found to be effective in improving the material resistance to plasma damage.

Mechanistic Study of CO 2 Plasma Damage to OSG Low k Dielectrics

A mechanistic study of CO2 plasma damage to OSG (organosilicate glass) low-k films was performed using both inductive-coupled ICP and capacitive-coupled RIE sources with varying plasma energy and density. The nature of the damage was investigated using spectroscopic ellipsometry (SE), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectrometer (XPS), and capacitance-voltage (C-V) measurements. The spectroscopic data were used to examine the origin of the dielectric loss based on the Kramers-Kronig dispersion relation to follow the change of the polarization components. Upon plasma treatment, the electronic dielectric constant was found to drop first and then rise to reach saturation while the ionic component increased and became saturated. Overall the dipolar contribution was found to dominate the dielectric loss. The extent of CO2 plasma damage was found to depend on the plasma density, plasma energy and the low k chemistry. Compared with the O2 plasma, the CO2 plasma induced less damage probably due to the compensation effect of the carbon in the CO2 plasma. While the RIE CO2 plasma induced mostly surface damage, the ICP plasma generated more damage in the bulk of the low k material.

300mm copper low-k integration and reliability for 90 and 65 nm nodes

The paper addresses critical issues associated with 90 and 65 nm copper low k interconnects. A stable baseline with >98% yield on 1E7via and 5m long serpent was established. Electromigration (EM) and IV breakdown performance was improved by optimizing the post CMP Cu pre-treatment and the dielectric barrier obtaining EM T/sub 0.1/ lifetime of greater than 10 yrs at 1.5 MA/cm/sup 2/ and >6MV/cm IV breakdown field. Detailed characterization of the impact of the barrier process on stress migration (SM) is presented. Extendibility of the process flow to sub-90nm interconnects and advanced dielectric (k<2.7) is shown.