ENGINEERING INDIVIDUAL GRAIN-BOUNDARIES USING A ZONE-CONFINING PROCESS IN CHEMICAL-VAPOR-DEPOSITED CU FILMS

Materials scientists have struggled for a while to find a process whic h can be used to engineer individual grain boundaries separating two a djacent grains. Considerable effort has also been devoted to finding a technique that can control the orientation of individual grains. A te mperature gradient applied during the chemical vapor deposition of thi n copper films provides an effect such that chains of grains oriented in the same direction are produced at chosen positions in the film. As a result of an interaction between defect migration and crystal growt h, interconnected grains, oriented in the [110] direction and separate d by twin grain boundaries, form chains along contours of equal temper ature, When the temperature gradient is small, low-angle tilt boundari es, low-energy coincidence-site boundaries, and twin boundaries are ob served. For a sharp temperature gradient, all boundaries are coherent twin boundaries. (C) 1997 American Institute of Physics.