Methods for controllable metal and barrier-liner recess
Methods of etching a metal layer and a metal-containing barrier layer to a predetermined depth are described. In some embodiments, the metal layer and metal-containing barrier layer are formed on a substrate with a first dielectric and a second dielectric thereon. The metal layer and the metal-containing barrier layer formed within a feature in the first dielectric and the second dielectric. In some embodiments, the metal layer and metal-containing barrier layer can be sequentially etched from a feature formed in a dielectric material. In some embodiments, the sidewalls of the feature formed in a dielectric material are passivated to change the adhesion properties of the dielectric material.
1. A processing method comprising:
providing a substrate comprising a first dielectric material with a second dielectric material deposited thereon, the second dielectric material having a thickness, the substrate comprising at least one feature formed in the first dielectric material and the second dielectric material, the at least one feature having at least one sidewall and a bottom, a depth of the feature defined from a top surface of the second dielectric material to the bottom of the feature, a barrier layer formed on the at least one sidewall and the bottom, and a metal layer formed on the barrier layer to fill the depth of the at least one feature, the second dielectric material having a higher density than the first dielectric material;
etching the metal layer to expose a portion of the barrier layer and to decrease a depth of the metal layer to a recessed depth;
etching the exposed portion of the barrier layer to remove the exposed portion of the barrier layer from the sidewall of the second dielectric material, wherein a top surface of the metal layer is even with a top of the barrier layer ±10 Å; and
repeating the etching of the metal layer and the etching of the barrier layer until a predetermined depth of the metal layer has been removed.
2. The method of claim 1 , wherein the first dielectric material comprises one or more of SiOC, porous organosilicate glass (p-SiCOH), doped or undoped silicate or SiOx.
3. The method of claim 1 , wherein the second dielectric material comprises one or more of SiN, SiCN, SiOC, AlN, AlC, AlOx, or a combination thereof.
4. The method of claim 1 , wherein the metal layer comprises one or more of Co, Cu, W, Ru, Ni, Ir, Pt or Si.
5. The method of claim 1 , wherein the barrier layer comprises a TiN.
6. The method of claim 1 , wherein the barrier layer comprises TaN with a Co or Ru liner, or Mn or Al containing compounds.
7. The method of claim 1 , wherein the metal layer comprises Co and the barrier layer comprises TiN.
8. The method of claim 1 , wherein the metal layer comprises Cu and the barrier layer comprises TaN with a liner comprising one or more of Co or Ru.