Aggressive cleaning process for semiconductor device contact formation
View Patent ↗A method of forming a contact through a material includes forming a via through a dielectric material and cleaning the via using a dilute hydrofluoric (DHF) acid solution. The method further includes depositing a barrier layer within the via and depositing metal adjacent the barrier layer.
1. A method of forming a contact, comprising:
forming a via through a dielectric material;
cleaning the via using a dilute hydrofluoric (DHF) acid solution and at least one of an ammonium hydroxide hydrogen peroxide mix (APM) or a sulfuric acid hydrogen peroxide mix (SPM),
wherein a concentration of HF to H 2 O within the DHF acid solution ranges from about 10:1 to about 500:1, wherein a concentration of NH 4 OH/H 2 O 2 /H 2 O in the APM ranges from about 1:1.2:8 to about 1:2.5:12 and wherein a concentration of H 2 SO 4 /H 2 O 2 in the SPM ranges from about 1:1 to about 5:1;
depositing a barrier layer within the via; and
depositing metal adjacent the barrier layer.
2. The method of claim 1 , further comprising:
forming a spacer on sidewalls of the via prior to cleaning the via.
3. The method of claim 1 , wherein depositing a metal comprises:
depositing tungsten adjacent the barrier layer to fill the via.
4. The method of claim 1 , wherein the barrier layer includes a layer of titanium.
5. The method of claim 4 , wherein the barrier layer further includes a layer of titanium nitride formed adjacent the layer of titanium.
6. A method of forming a contract, comprising:
cleaning a via that extends through a dielectric layer using a dilute hydrofluoric (DHF) acid solution and at least one of an ammonium hydroxide hydrogen peroxide mix (APM) or a sulfuric acid hydrogen peroxide mix (SPM),
wherein a concentration of HF to H 2 O within the DHF acid solution ranges from about 10:1 to about 500:1, wherein a concentration of NH 4 OH/H 2 O 2 /H 2 O in the APM ranges from about 1:1.2:8 to about 1:2.5:12 and wherein a concentration of H 2 SO 4 /H 2 O 2 in the SPM ranges from about 1:1 to about 5:1;
depositing, after cleaning the via, a first barrier layer comprising titanium within the via;
depositing a second barrier layer comprising titanium nitride (TiN) over the first barrier layer; and
forming a contact within the via adjacent the second barrier layer.
7. The method of claim 6 , further comprising:
forming a spacer on sidewalls of the via prior to the cleaning.
8. The method of claim 6 , wherein forming the contact within the via comprises:
forming tungsten over the second barrier layer.