Specific Process Knowledge/Thin film deposition/Deposition of Titanium: Difference between revisions
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== Comments: Adhesion layer == | == Comments: Adhesion layer == | ||
'''Ti as adhesion layer''' | '''Ti as an adhesion layer''' | ||
Titanium is most often used as a adhesion layer for other metals, like for example gold. Gold does not stick very well to Si, and to prevent it to come off in future process steps or in the final application, a layer of Ti (or Cr) is often deposited onto the wafer. | Titanium is most often used as a adhesion layer for other metals, like for example gold. Gold does not stick very well to Si, and to prevent it to come off in future process steps or in the final application, a layer of Ti (or Cr) is often deposited onto the wafer. | ||
The most common thickness of the Ti adhesion layer is '''10 nm'''. Also layers with a thickness of 5 nm is used. | The most common thickness of the Ti adhesion layer is '''10 nm'''. Also layers with a thickness of 5 nm is used. Read more about [[Specific Process Knowledge/Thin film deposition/Deposition of Gold/Adhesion layers|gold adhesion layers]]. | ||
'''Very thin adhesion layers''' | '''Very thin adhesion layers''' | ||
If it is important to have a very thin Ti layer, it is possible to use even thinner adhesion layers. There | If it is important to have a very thin Ti layer, it is possible to use even thinner adhesion layers. There is some experience in using a 3 nm Ti as adhesion layer for a 200 nm thick gold layer. In this case a Si wafer was dipped in buffer and rinsed in water immediately before being placed in the PVD equipment (Wordentec). After an RF clean process of the wafer, 3nm of Ti and 200 nm of Au was deposited, and this worked fine during futher processing. | ||