Reliable laser programmable gate array technology

Field-programmable gate arrays have become popular ever since their introduction. Compared to other digital circuit implementation media, they have lower non-recurring engineering (NRE) cost and rapid turnaround with the penalties of reduced speed and larger size. Thus better FPGA programmable switch technology is desired in order to gain speed and density advantages. In this paper, laser-induced MakeLink™ technology is proposed as a programmable switch element. The electrical resistance is as low as 0.8 Ω to 11 Ω, depending on the size of the link, which is 2-3 orders smaller than that of NMOS transistor in a SRAM based FPGA. Thus the speed improvement for laser field-programmable gate array (LFPGA) is significant. Other features of laser-induced vertical links technology, such as small size and radiation hardness, can also greatly improve the FPGA performance. The cluster-based LFPGA with 128 by 64 basic logic elements (BLE) is laid out under a 0.5 μm commercialized technology. The chip size is about 138 mm².