Characterization of PECVD Ti process and development of a plasma-less chlorine clean for process repeatability in advanced DRAM manufacturing

The TiCl4 based CVD-Ti process has been identified as the candidate of choice for the advanced contact metallization. A BKM wet clean recovery (WCR) procedure, involving extended chamber seasoning, has been developed for the CVD-Ti process. The new WCR methodology takes only 5 wafer processing to stabilize the CVD-Ti chamber condition and film properties. It has been found that a chamber seasoning for 200 sec, performed after every idle time (greater than 15 min.) and thermal periodic clean (at wafer count # 200), helps to maintain the CVD-Ti process performance. The reliability of the new chamber operating procedures was validated through a successful 3000 wafer marathon demonstration.