LASER INDUCED LOCAL MODIFICATION OF SILICON MICRODEVICES: A NEW TECHNIQUE FOR TUNING ANALOGUE MICROELECTRONICS

摘要

Highly accurate resistances can be made by iteratively laser inducing local diffusion of dopants from the drain and source of a gateless field effect transistor into the channel, thereby forming an electrical link between two adjacent p-n junction diodes. Using transmission electron microscopy, we showed that the laser induced diffusible resistance can be performed without any structural modification to the microdevices. Current-voltage (Ⅰ-Ⅴ) characteristics of these new microdevices are shown to be linear at low voltages and sublinear at higher voltages where carrier mobility is affected by the presence of high fields. A process model involving an approximate calculation of the laser melted region in which the dopant diffusion occurs has been developed. Experimental results are well described by the proposed model.