Avoiding gate metal via shorting to source or drain contacts
Techniques relate to forming a gate metal via. A gate contact has a bottom part in a first layer. A cap layer is formed on the gate contact and first layer. The gate contact is formed on top of the gate. A second layer is formed on the cap layer. The second layer and cap layer are recessed to remove a portion of the cap layer from a top part and upper sidewall parts of the gate contact. A third layer is formed on the second layer, cap layer, and gate contact. The third layer is etched through to form a gate trench over the gate contact to be around the upper sidewall parts of the gate contact. The gate trench is an opening that stops on the cap layer. Gate metal via is formed on top of the gate contact and around upper sidewall parts of the gate contact.
1. A semiconductor device having a gate metal via, the semiconductor device comprising:
a gate contact having a bottom part in a first layer;
a cap layer formed on the first layer so as to abut sides of the gate contact;
a second layer formed on the cap layer and a third layer formed on top of the second layer; and
a gate metal via formed on top of the gate contact and around upper sidewall parts of the gate contact, the gate metal via formed through the second and third layers to stop on the cap layer.
2. The semiconductor device of claim 1 , wherein the first layer includes a source contact.
3. The semiconductor device of claim 1 , wherein the first layer includes a drain contact.
4. The semiconductor device of claim 1 , wherein the first layer includes a gate and the bottom part of the gate contact.
5. The semiconductor device of claim 4 , wherein the gate contact is formed on top of the gate.
6. The semiconductor device of claim 5 , wherein the cap layer includes a vertical cap layer sidewall formed on both sides the gate contact.
7. The semiconductor device of claim 6 , wherein a metal of the gate metal via lands on top of the vertical cap layer sidewall on both sides of the gate contact, thereby wrapping around the upper sidewall parts of the gate contact.
8. The semiconductor device of claim 1 , wherein the cap layer and the second layer are different materials.
9. The semiconductor device of claim 1 , wherein the cap layer protects a source contact and a drain contact.
10. The semiconductor device of claim 9 , wherein the gate metal via is formed of a metal.
11. The semiconductor device of claim 10 , wherein the cap layer prevents the metal of the gate metal via from contacting either the source contact or the drain contact.
12. The semiconductor device of claim 1 , wherein a source contact, a drain contact, and a gate are formed on a substrate.
13. The semiconductor device of claim 12 , wherein the gate includes a high-k metal.
14. The semiconductor device of claim 12 , wherein the gate includes hafnium dioxide.
15. The semiconductor device of claim 12 , wherein the gate includes titanium dioxide.
16. The semiconductor device of claim 12 , wherein the substrate is a fin.
17. The semiconductor device of claim 12 , wherein the substrate includes silicon.
18. The semiconductor device of claim 12 , wherein the substrate includes silicon germanium.
19. The semiconductor device of claim 12 , wherein the substrate includes p-type dopants.
20. The semiconductor device of claim 12 , wherein the substrate includes n-type dopants.