Model to Plan and Control the Generational Transition of DRAM Industry

DRAM industry is not only among the largest manufacturing industries in the world, but also the most competitive. Furthermore, due to DRAM business is characterized by short life cycles, along with highly competition, the manufacturers are forced to migrate to advanced technology quickly. Under this circumstance, the manufacturers have to launch new technology and purchase generational equipment to meet the market demand and reduce manufacturing cost frequently. This paper investigates the technology generational transition of DRAM industry from manufacturing and planning perspectives. The concept of TOC is applied to schedule the production plan of the new/old products. Regarding to shop floor control, three definitions of cycle time are used to diagnose the production status. Finally, the workload ratio of bottleneck is used for the release decision to adjust the rhythm of production.

Taiwan DRAM Industry in 2009

Under the impact of the 2008 financial tsunami, the Ministry of Economic Affairs, R.O.C., made a proposal to the Execution Yuan in March 2009 regarding the renovation plan of Taiwan DRAM industry. This plan was hopefully to establish Taiwan Memory Company (TMC) with private investors to renovate Taiwan DRAM industry. However, under media pressure, in July 2009, the original plan was altered to invite any DRAM company that wished to propose a renovation plan and needed government funding to file an application within three months. In August 2009, Taiwan Innovation Memory Company (TIMC) was officially established. This case aims to discuss the difficulties of Taiwan DRAM industry and the feasibility of the renovation plan through the establishment of TMC by its historical background and potential impacts. The key role of this case is Mr John Hsuan, CEO of TMC, and the decision-making focus is the Renovation Plan of Taiwan DRAM Industry under the charge of the Ministry of Economic Affairs. This covers the fourth quarter of 2008 to the first quarter of 2010. The purpose of the DRAM industry renovation plan was to sustain the technology and the industry, not any individual company. Therefore, the plan did not solve the financial problems of any DRAM companies. Can the DRAM industry renovation plan successfully turn Taiwan's DRAM industry around in a financial crisis and upgrade the competitive advantage of the nation?

ADVANCED CONCEPTS FOR FLOATING-BODY MEMORIES

With 30nm-class memory cells in production and 20nm-class (20-29nm feature-size) memory targeted for next year, the standard 1-Transistor + 1-Capacitor (1T+1C) DRAM industry is making prominent efforts to improve the scalability of the cell capacitor while maintaining the minimum capacitance requirements for state discrimination, immune to noise (C~25fF/cell). To achieve the capacitance requirement, the DRAM cell has evolved from its initial planar implementation to complex three-dimensional structures. The increment in complexity and the large difference in size between the transistor and capacitor of each cell have motivated the search for Floating-Body Single-Transistor DRAM (1T-DRAM). The underlying idea behind 1T-DRAMs is the development of single-device memory cells with a pronounced hysteresis effect and fast operation. This chapter is focused on the floating-body effect as a primary source of hysteresis. We present new concepts able to deal with the basic limitations of 1T-DRAM while maintaining its simplicity. The floating-body 1T-DRAMs can be reconciled with the aggressive scaling constrains by considering new ideas which make possible the coexistence of electron and holes in the same ultrathin transistor. The best approach is to isolate each type of carrier in an specific potential well which is not created specifically by the bias conditions (unlike standard 1T-DRAMs) but by the physical structure of the device.