| 摘要 |
A method of manufacturing a dielectric film for a capacitor in a DRAM. A native oxide layer is removed using a rapid ramp process at a pressure lower than 10-5 torr. A nitridation is performed to form a dielectric layer on the surface of a storage electrode. A silicon nitride layer is formed on the dielectric layer. The rapid ramp process is started at a temperature of about 450-550° C. The temperature is raised at a rate of about 80-120° C./minute. The rapid ramp process is stopped at about 700-850° C. The nitridation is performed using a source gas, such as ammonia at about 700-850° C. for a relatively long time of about 10-60 minutes. The dielectric layer includes silicon nitride or silicon-oxy-nitride. An oxide layer is further formed on the silicon nitride layer. The oxide layer is formed by, for example, a rapid thermal process. A gas used in the rapid thermal process can be selected from a group including nitrogen monoxide (N2O), oxygen and combinations of nitrogen monoxide (N2O) and oxygen. The dielectric film structure of the capacitor of the invention can be a double-layer structure such as silicon nitride/silicon oxide or a mono-layer structure, such as silicon nitride.
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