Abstract

We present results on the photoconductive generation¹ and on the propagation of picosecond electrical pulses on transmission lines of dimensions compatible with microelectronics applications. The structure studied consists of a pair of coplanar aluminum lines of 1.2 μm width separated by 2.4 μm. These lines are deposited on polysilicon which acts as a photoconductor² for pulse generation and waveform sampling. The undoped polysilicon is first annealed to increase the carrier mobility and subsequently implanted in order to reduce the carrier lifetime similarly to ref. ¹. The results show the possibility of full integration of this technology with either bipolar or MOS silicon devices for in situ characterization with suitable voltage levels. We have studied various structures involving these transmission lines such as transmission through tapers and wire-bonds or cross-talk experiments. For these experiments we use the "sliding contact"³ technique of excitation which has the advantage of a very balanced excitation of the line. We also successfully extend this technique to waveform detection on the transmission line. This technique samples the waveform in a true differential way which allows us to fully characterize cross-talk between two adjacent pairs of lines. This the first study of picosecond electrical pulses in a true microelectronics environment.

© 1986 Optical Society of America