Reduction of bulk and interface defects by network self-organizations in gate dielectrics for silicon thin film and field effect transistors (TFTs and FETs, respectively)

Studies of binary chalcogenide alloys have established that the onset of network rigidity is generally delayed by a network self-organization resulting in an intermediate phase with significant deviations from mean-field chemical bonding. In GexSe1−x, the onset of local chemical bonding rigidity occurs for a mean-field coordination, rc = 2.4 at x = 0.2, but percolation of stress resulting in network rigidity is delayed until rc = 2.52. This paper demonstrates that low levels of electrically active defects in gate dielectrics for (i) thin film transistors (TFTs) in liquid crystal displays (LCDs), and (ii) aggressively-scaled metal- oxide-semiconductor field effect transistors (MOSFETs) are derived from similar network self-organizations that occur for a narrow range of dielectric compositions. The dielectrics of this article are non-crystalline (nc-) SixNyHz alloys in which a chemical self-organization occurs during deposition at 300 °C, and nc-(SiO2)x(Si3N4)y(ZrO2)z alloys in which it occurs during post-deposition annealing at ∼900 °C. For each of these alloys, the values of x, y and z, are approximately 0.3, 0.4 and 0.3.