TY - JOUR
T1 - A novel wafer reclaim method for amorphous SiC and carbon doped oxide films
AU - Tsui, Bing-Yue
AU - Fang, Kuo Lung
PY - 2005/11/1
Y1 - 2005/11/1
N2 - Amorphous SiC (a-SiC) films are the most promising dielectric diffusion barriers to replace silicon nitride in Cu-interconnect technology. However, reclaim of wafers with a-SiC films is a challenge issue for mass production. In this paper, a novel wafer reclaim method is proposed. It is observed that a-SiC can be oxidized to SiO 2 in both dry O 2 and steam ambients at temperatures as low as 550°C. The oxidation mechanism can be described by the Deal-Grove model that is traditionally used to describe oxidation of Si. Experiments prove that the oxidation process is clean and uniform. It is also observed that carbon doped oxide (CDO) films can be oxidized easily, too. Therefore, oxidation followed by HF etching could be a universal process to reclaim wafers deposited with a-SiC or CDO films. Since the oxidation rate of Si substrates at medium temperatures is much lower than that of a-SiC and CDO films, the oxidation process is virtually self-limiting. Compared with a traditional reclaim method based on wafer polishing, this universal oxidation-etching method exhibits great benefits in terms of low cost, high throughput, and the ability to perform nearly unlimited numbers of reclaim cycles.
AB - Amorphous SiC (a-SiC) films are the most promising dielectric diffusion barriers to replace silicon nitride in Cu-interconnect technology. However, reclaim of wafers with a-SiC films is a challenge issue for mass production. In this paper, a novel wafer reclaim method is proposed. It is observed that a-SiC can be oxidized to SiO 2 in both dry O 2 and steam ambients at temperatures as low as 550°C. The oxidation mechanism can be described by the Deal-Grove model that is traditionally used to describe oxidation of Si. Experiments prove that the oxidation process is clean and uniform. It is also observed that carbon doped oxide (CDO) films can be oxidized easily, too. Therefore, oxidation followed by HF etching could be a universal process to reclaim wafers deposited with a-SiC or CDO films. Since the oxidation rate of Si substrates at medium temperatures is much lower than that of a-SiC and CDO films, the oxidation process is virtually self-limiting. Compared with a traditional reclaim method based on wafer polishing, this universal oxidation-etching method exhibits great benefits in terms of low cost, high throughput, and the ability to perform nearly unlimited numbers of reclaim cycles.
KW - Amorphous silicon carbide
KW - Low dielectric constant
KW - Wafer reclaim
UR - http://www.scopus.com/inward/record.url?scp=28644448563&partnerID=8YFLogxK
U2 - 10.1109/TSM.2005.858501
DO - 10.1109/TSM.2005.858501
M3 - Article
AN - SCOPUS:28644448563
VL - 18
SP - 716
EP - 719
JO - IEEE Transactions on Semiconductor Manufacturing
JF - IEEE Transactions on Semiconductor Manufacturing
SN - 0894-6507
IS - 4
ER -