Advanced Photovoltaics and Electronics: Device Reliability and Lifetime Performance Applications for Thin Film Electronics and Photovoltaics 

New date to be decided

TECHNOLOGY FOCUS
The further diversification and growth of semiconductor industry and the rapid growth of photovoltaic industry, including thin film photovoltaics, rely on technical and economic targets. Several technologies are emerging currently, such as new devices and materials, thin films based on Si or inorganic compound semiconductors, as well as inorganic and organic nanostructures and nano-composites. Potential degradation mechanisms in thin films and nanostructures, that determine the long-term behavior of devices and the reliability of products, needs to be studied for each technology. The integration of new 
materials is a particular challenge. Experimental studies and modeling/simulation are needed to provide the knowledge, which will be necessary to guarantee the required product reliability. 

COURSE CONTENT
The subjects covered in this course extend from fundamentals of processing of thin films and materials-related topics up to quality engineering and reliability. Specific modifications of technologies and products will be explained for several thin film technologies. Potential degradation mechanisms and the long-term behavior of products will be discussed. Experimental studies of degradation processes and numerical simulations based on physical models will be shown. In-situ experiments of reliability-limiting processes will be discussed for advanced interconnect systems. The role of interfaces and nanostructures will be explained both from the scientific point of view but also from the aspects of process control and reliability. 

WHO SHOULD ATTEND
This course is addressed to engineers and scientists who need state-of-the-art knowledge of material properties and reliability for modern electronics and thin-film photovoltaics. 

Thursday - E. Zschech am / V. Sukharev pm
LONG-TERM BEHAVIOR AND DEGRADATION MECHANISMS 
OF ELECTRONIC DEVICES AND PRODUCTS 

In-situ Experimental Studies of Interconnect Degradation, Interfaces and Microstructure 
This lecture will deal with potential degradation mechanisms and the long-term behavior of microelectronic devices and products for the new technology generation. Scaling down and the use of new materials are particular challenges. Experimental studies of degradation processes and numerical simulations based on physical models will be explained. Particularly, in-situ experiments to observe electromigration and stress migration in on-chip interconnects are shown. Microstructure and stress are discussed for Cu/low-k interconnects structures, including and the effect of 3D IC integration on stress in device structures. 

Modeling and Simulation of Processes, Layout-induced Variations and Reliability 
In this lecture, the current status of the physics-based process and reliability simulations is discussed. Process and device simulation is traditionally used for the development of new semiconductor processes and devices. Recently a serious problem with a traditional TCAD employment for the advanced technology nodes was raised. It is related to increased in-die variations in electrical characteristics of VLSI devices caused by layout shapes and pattern density variations. These variations affect all important characteristics of the semiconductor chip such as power, timing, leakage. Additional scale and physical dimensions should be added to the multi-physics simulation scheme. The necessity of die-scale models will be demonstrated on examples of plasma-assisted process simulations.This provides a better link between wafer-scale and feature-scale simulation tools, and, which is critical, a way to model layout-induced intra-die device variations. New approaches for modeling and simulation of layout-induced variation regarding the strain engineering and 3D integration will be discussed. The necessity of new physical models will be demonstrated on simulation examples of the stress evolution during electromigration and stress migration in dual-inlaid Cu interconnects for the prediction of the sites for void nucleation and for the description of void movement and growth. 

Friday - W. Hoffman am / M. C. Lux-Steiner pm
SYNERGETIC ASPECTS OF ELECTRONICS AND PHOTOVOLTAICS 

Thin Film Technologies for Photovoltaics 
Thin film technologies, based on Physical Vapour Deposition (PVD) and Plasma Enhanced Chemical Vapour Deposition (PECVD), have been developed for a number of hightech industries over the last decades. Prominent examples are the semiconductor and display industries as well as large area architectural glass and flexible substrates deposition industries. Inherently linked with this development was the pronounced decrease of the production-cost-perunit-area, explaining in many cases the well-known price experience-curve for products in the respective industry. Analysing the price-experience-curve for c-Si modules over the last 30 years and extrapolating for the coming 10 years, it will become evident that cost efficient thin films on c-Si are a prerequisite to meet the anticipated cost and price goals. Including the possible price-experience-curve for thin film technologies - a-Si, a-Si/uc-Si, CI(G)S and CdTe/CdS - and their potential development in the coming years, we will see even more similarities with large area deposition technologies from other industries. As photovoltaics will demonstrate to become one of the major energy providers in the future, by helping significantly to meet the goal of 100% end energy by only renewable technologies in 2050, we will see a huge increase of appropriate thin film technologies in the years to come. 

Interfaces and Nanostructures in Electronics and Thin-Film Photovoltaics 

SYNERGETIC ASPECTS OF ELECTRONICS AND PHOTOVOLTAICS 

Interfaces and Nanostructures in Electronics and Thin-Film Photovoltaics 
This lecture will address topics in materials science, device fabrication, and device performance with the following focus: Thin-film photovoltaic devices have the potential for cost reduction being necessary for grid-parity and even beyond. Present thin-film technologies, based on amorphous and/or microcrystalline sili con on Cu(In,Ga)(S,Se)2 or on CdTe, are now in a crucial stage of their economic development and will prove their promises in the near future. R&D aim to guide the multilayer devices to their maximum 
conversion efficiencies and, at the same time and consequently, production costs and material consumption are reduced. For systematic optimisation, standard and highly sophisticated analytical tools are used to provide compositional, chemical, structural, and electronic information on all depth regimes from the very surface to the surface-near bulk of materials. In addition to today's technologies, meso- and nanoscale photovoltaic approaches envisage long-term perspectives beyond that horizon in both efficiency and cost reduction. Hereto, new concepts, primarily enabled by nanotechnology, will be systematically utilized to enhance light confinement to control current management, to accelerate charge separation, and to facilitate assembly and design of functional components in devices like absorbers, contacts, reflection, and anti-reflection layers. Especially, such concepts, based on physical principles that are not common in photovoltaics so far, must be systematically investigated in order to pace off the physical limits of power conversion efficiencies.The wide field of opportunities will be along the concept lines: (i) inorganic nanostructured films and quantum size materials, (ii) organics, and (iii) nanostructured hybrid material systems. Verifying all the promising concepts is a major challenge for cost-effective thin-film processing, enhanced interface engineering, validity of theoretical considerations and device modelling. 

See also course #65 Megafunction Electronics and Photonics Based on 3D Integration: Applications for 3D Si-based ICs, Flexible Polymer Electronics, Thin Film Solar Cells, and OLEDs