# Roadmapping of Nanoelectronics for the New Electronics Industry
## 3 Roadmap Methodology Background and Historical Evolution  
The IRDS is the third generation of the Roadmap, initially described empirically by [PERSON] in 1965 [5]. His prediction mentioned that the number of transistors that could be integrated into a single chip would double each year for the next ten years. This was found to be true and in 1975 he revised his prediction by doubling the number of transistors every 2 years [6]. He also identified three main contributors to these results: the architecture of integrated circuits, the scaling down of devices, and the ability to produce cost effectively larger dice thanks to high manufacturing efficiencies. [PERSON] published also some rules for predicting the performance of miniaturized transistors [7]. The semiconductor industry scrupulously followed these rules for the next fifteen years. [PERSON]'s methodology was correct till about 2005. Inversely, Moore's Law is still valid today and is predicted to continue to hold for at least the next ten years.  
In 1991, it was proposed by the universities, industry and government organizations in the US to write a document with the future evolution governing the next steps of the semiconductor and electronics industries for the next 15 years. Eleven Technology Working Groups (TWGs) were indeed formed for this purpose. In 1992, the National Technology Roadmap for Semiconductors (NTRS) was published, followed by publications in 1994 and 1997.  
In 1996 it was clear that major obstacles will be encountered in the next years; for example, the gate dielectric becoming too thin by 2005 at the latest. A full re-engineering of the transistor was necessary to overcome these limits. This was a worldwide problem affecting the entire semiconductor and electronics industries.  
The International Technology Roadmap for Semiconductors (ITRS) was formed in 1998 to overcome these roadblocks with the involvement of partners from Europe, Japan, Korea, Taiwan and US. A revolutionary strategy to completely change how transistors are structured and manufactured was proposed. The worldwide collaboration between universities, suppliers, national programs and consortia around allowed the development of strained silicon, high-k/metal-gate, novel device architecture such as FinFET, in manufacturing. In 2011 this effort was finalized and allowed to save the semiconductor and the electronics industry.  
Historically, the semiconductor industry provided the needed blocks to system integrators. New products with enhanced performance than the previous ones were enabled by an improved technology. The pace at which the whole electronics industry ecosystem was moving forward was guided by the Integrated device manufacturers (IDM) together with software companies for operating systems and applications. The transistor scaling, the challenges to be overcome, the performance of integrated circuits were forecasted by the NTRS and IRDS Roadmaps.  
In the last 15 years, system integrators have regained full control of the business model due to the development of design houses and foundries that have revolutionized the semiconductor industry. System requirements are driving any new product design cycle and related needs are transmitted through the manufacturing production chain to the semiconductor manufacturers. The design of a new PC is presently not triggered by a faster processor, and on the contrary new ICs and other functionalities are required by the design of a new smart phone. On the other hand, limits of traditional 2D integration lead to a substantial challenge for semiconductor industry to continue scaling at historical rates. In 2016, the introduction of new very innovative 3D transistors, memory cells and other 3D IC structures has launched another revolution in the way ICs will be designed and produced in the next decade.