Summary of information:

Guangzhou Nine Chip Electronic Technology Co., Ltd. is a high -tech enterprise focusing on voice technology research. It mainly provides voice IC, voice chip, voice module, voice bips, voice alarm, forklift speeder, automotive speed limiter and other businesses Serve....

For a long time, aluminum interconnection metal layers of voice chips have been used. Using a proportional design method, as the characteristic size becomes smaller and smaller, the speed of the integrated circuit is getting faster and faster, and the clock frequency of the microprocessor made of 180nm technology has exceeded 1GHz. In this case, the fine aluminum connection resistance on the voice chip has become the main factor affecting the speed of integrated circuit.

A few years ago, IBM launched copper interconnection technology. The use of copper replacement aluminum as interconnected metals is recognized as an important method of reducing the interconnected resistance and improving the performance of integrated circuit. First of all, this is because the resistance of the copper interconnection is compared to the aluminum interconnection. It can be reduced by 40%under the same cross -area. The use of copper interconnection can reduce the resistance of the interconnection on the chip, or keep the resistor in keeping the resistor. Under the circumstances, the thickness of the interconnected metal is reduced to reduce the coupling capacitance between the interconnection in the same layer, thereby reducing the signal delay of coupling noise and interconnect. Secondly, in recent years, the double -Masculogy craft structure, which has been used in copper interconnections, has been successfully developed. It can reduce the expensive process steps in chip manufacturing and reduce manufacturing costs. Furthermore, in terms of electricity migration, copper is significantly better than aluminum. Therefore, when the characteristic size is 180nm or more, copper will replace aluminum for voice chip manufacturing processes.

At the 12 -year SEMI seminar, IBM and Infineon (formerly Siemens Corporation semiconductor department) published the CMOS 7S and 7SF processes, which received widespread attention. It uses a full -integrated ULSICMOS/copper interconnection technology. The copper interconnection layer can be as many as 6 layers. The length of these two processes (on the graphics) is 0.20 μm and 0.18 μm, respectively. 0.11 μm (to NFET), the center distance of the metal contact is 0.63 ~ 0.81 μm (for CMOS 7S) and 0.44 ~ 0.46 μm (CMOS 7SF).

While affirming the superiority of copper interconnection technology, some experts also emphasize the challenges faced by the technology in terms of material integration and reliability. Because copper is easy to diffuse into silicon and most of the electrical media, it must use metal (such as TA, TAN) and medium (such as SIN, SIC) diffusion blocking layer "packaging" to avoid leakage and leakage between metal lines and electricity lines and Degenerate of transistor performance on the chip. At the same time, when the chip is working, the electric field applied between the adjacent metal wires has also greatly increased the diffusion rate of copper, so it is important to ensure that the absolute integrity of the "blocking layer" is important to the long -term reliability of the device. When using copper -connected technology, how to avoid the pollution of copper in voice chip manufacturing has also become an important issue in the manufacturing process.

In general, it is an inevitable trend to include copper interconnection technology into 180Nm or smaller characteristic size, but as a basic manufacturing process in large -scale production, it is still in the early stages of development. At present Both companies and the United States Sematech are carrying out further research and development work.

Editor -in -chief (Nine Chip Electronics)