Self-organized structuring of W/C multilayers on Si substrate

After aging at room temperature for several months W/C multilayers (20 periods, single layer thicknesses in the nanometer range) grown on Si-(111) substrates by pulsed laser deposition (PLD) developed homogeneously wrinkled surfaces. Their structures were studied by optical microscopy, atomic force microscopy and X-Ray diffractometry. Typical dimensions of debonded areas are some 100µm in length, about 40 mu m in width and 2-3 mu m in height. The formation of wrinkles is accompanied by an increase in the free surface by 1%-2%. Stress relaxation is considered the driving force of this phenomenon.