Development of a manufacturable low pressure ROXNOX oxidation process [for CMOS technology]

Development work was completed on a ROXNOX oxidation to harden the gate oxide against hot carriers. Although device lifetime criteria were met and exceeded, there were serious manufacturing problems which remained. These problems included nonuniform oxide, high particle counts and excessive equipment failures due to the high temperature required for the ROXNOX oxidation process. A series of equipment and process solutions resulted in a factor of 2 film uniformity improvement, a factor of 2 reduction in average particle counts and a reduction of the occurrence and magnitude of particle spikes as well as improvement in equipment availability by 20%.