TIME-DEPENDENT DIELECTRIC-BREAKDOWN MEASUREMENTS ON RPECVD AND THERMAL OXIDES

Time dependent dielectric breakdown (TDDB) measurements have been made on a 96 Angstrom oxide deposited by remote plasma enhanced chemical vapor deposition (RPECVD) upon a 300 degrees C Si(100) device grade substrate. The oxide was used to form an array of 10 x 10 mu m square capacitors. The oxide was then subjected to electron injection from the substrate at 0.1 A/cm(2) constant stress current. The charge-to-breakdown (QBD) was measured and found to be 39 +/- 3 C/cm(2). A similarly fabricated 92 Angstrom thermal oxide capacitor array showed a QBD value of 49 +/- 4 C/cm(2). Analysis of the forcing voltage during stress showed the RPECVD oxide to have an initial trap density of 1.76 +/- 0.07 x 10(18) cm-(3,) compared to 5.6 +/- 0.2 x 10(17) cm(-3) for the thermal oxide. In both cases, at 0.1 A/cm(2), the stress voltage across the oxide rose linearly with time. Trap generation rates of 3.1 +/- 0.2 x 10(16) cm(-3) s(-1) and 2.0 +/- 0.2 x 10(16) cm(-3) s(-1) were measured for the RPECVD and thermal oxides, respectively. The TDDB data were analyzed to find breakdown occurring in localized areas of (68 +/- 11 Angstrom)(2) containing 18 +/- 3 filled electron traps.