The effect of <100> orientation of fabrication on high-density, high-speed monolithic circuits

Electrical and material limitations in the fabrication of monolithic circuits can be directly attributed to theg orientation commonly used for silicon substate material. It has been found that the orientation provides significant improvements in material perfection and accompanying increased junction breakdown voltage and device beta. Epitaxial film growth is dependent on crystallographic characteristics of the starting substrate. substrates receiving a pre-epitaxial oxidation and diffusion have exhibited a high imperfection density which yields as high as 50,000/cm²stacking faults after film growth. These have been reduced by orders of magnitude by using 100 substrates. A direct consequence of this would be higher monolithic circuit yields. Also, the slow growing orientation exhibits a horizontal mode of growth which can be greater than the vertical epitaxial thickness. This could yield significant errors in diffusion mask alignment with respect to sites fabricated prior to deposition. 100 material virtually eliminates this effect, allowing the design of more densely packed circuits.