Effect of Low-Temperature Anneal during Multilevel Metallization Process on Plasma-Induced Oxide Damage

It has been shown that oxide damage monitoring methods that depend on device characteristics without forming gas anneal can lead to a misleading conclusion if the devices have multilevel metallization (MLM). This is because metal etching-induced oxide damage is affected by low-temperature anneals as low as 300/spl deg/ during the MLM process. To correctly evaluate reliability of MOSFETs with various antenna structures after the MLM process, latent oxide damage must be monitored after a full process using stress tests such as hot carrier stress test.