Granted Patent B2

US 12,245,439 · App. 17/744,881 · Granted Mar 4, 2025

Inventor: Yaojian Leng (Vancouver, WA)

Assignee: Microchip Technology Incorporated

H10D1/042H01L21/76877H01L21/76883H01L23/5223H01L23/5226H10D1/043H10D1/692H10D1/714

Abstract

Claims (60)

1. A method, comprising:

forming a tub opening in a dielectric region;

depositing a conformal metal layer over the dielectric region and extending down into the tub opening, the deposited conformal metal forming (a) a cup-shaped conformal metal layer region in the tub opening and (b) a lateral conformal metal layer region extending laterally outwardly from a top of the cup-shaped conformal metal region;

removing a corner region of the conformal metal layer at a corner defined between the cup-shaped conformal metal layer region and the lateral conformal metal layer region by a process including:

forming an oxide layer having an opening over the corner region of the conformal metal layer; and

etching through the opening in the oxide layer to remove the corner region of the conformal metal layer;

wherein a remaining portion of the cup-shaped conformal metal layer region defines a bottom electrode cup including (a) a laterally-extending bottom electrode cup base and (b) a bottom electrode cup sidewall extending upwardly from the laterally-extending bottom electrode cup base;

depositing an insulator layer including (a) an insulator cup in an opening defined by the bottom electrode cup and (b) an insulator flange extending laterally outwardly from the insulator cup and extending laterally over an upper surface of the bottom electrode cup sidewall;

depositing a top electrode layer over the insulator layer and extending into an opening defined by the insulator cup, wherein the top electrode layer includes a top electrode cap region extending over the insulator flange, wherein the insulator flange is arranged between the top electrode cap region and the upper surface of the bottom electrode cup sidewall;

removing upper portions of the top electrode layer, insulator layer, and conformal metal layer, wherein (a) a remaining portion of the top electrode layer defines a top electrode, and (b) a remaining portion of the insulator layer defines an insulator including the insulator cup and the insulator flange; and

forming a top electrode connection pad conductively connected to the top electrode;

wherein the top electrode is insulated from the upper surface of the bottom electrode cup sidewall by the insulator flange.

2. The method of claim 1 , wherein forming the oxide layer having the opening over the corner region of the conformal metal layer comprises performing a high density plasma (HDP) process including depositing of the oxide layer and sputter etching to remove a corner region of the deposited oxide layer over the corner region of the conformal metal layer thereby forming the opening over the corner region of the conformal metal layer.

3. The method claim 1 , wherein removing the corner region of the conformal metal layer comprises sputter etching the conformal metal layer.

4. The method of claim 1 , comprising:

forming a bottom electrode base in a lower metal layer,

wherein the dielectric region is formed over the lower metal layer and wherein the tub opening is formed over the bottom electrode base.

5. The method of claim 4 , wherein the lower metal layer comprises a metal interconnect layer.

6. The method of claim 4 , wherein forming a bottom electrode base in a lower metal layer comprises forming a metal silicide on a polysilicon region.

7. The method of claim 1 , wherein removing upper portions of the top electrode layer, insulator layer, and conformal metal layer comprises performing a planarization process defining a planarized top surface including a top surface of the dielectric region, a top surface of the top electrode layer, and a top surface of the insulator layer.

8. A method, comprising:

patterning and etching a dielectric layer to concurrently form a tub opening and a bottom electrode contact opening;

depositing a conformal metal layer in the tub opening and the bottom electrode contact opening concurrently, wherein the conformal metal layer deposited in the tub opening forms (a) a cup-shaped conformal metal layer region and (b) a lateral conformal metal layer region extending laterally outwardly from a top of the cup-shaped conformal metal region, and wherein the conformal metal layer deposited in the bottom electrode contact opening defines a bottom electrode contact; and

removing a corner region of the conformal metal layer at a corner defined between the cup-shaped conformal metal layer region and the lateral conformal metal layer region, wherein a remaining portion of the cup-shaped conformal metal layer region defines a bottom electrode cup including (a) a laterally-extending bottom electrode cup base and (b) a bottom electrode cup sidewall extending upwardly from the laterally-extending bottom electrode cup base;

depositing an insulator layer including (a) an insulator cup in an opening defined by the bottom electrode cup and (b) an insulator flange extending laterally outwardly from the insulator cup and extending laterally over an upper surface of the bottom electrode cup sidewall;

depositing a top electrode layer over the insulator layer and extending into an opening defined by the insulator cup, wherein the top electrode layer includes a top electrode cap region extending over the insulator flange, wherein the insulator flange is arranged between the top electrode cap region and the upper surface of the bottom electrode cup sidewall;

removing upper portions of the top electrode layer, insulator layer, and conformal metal layer, wherein (a) a remaining portion of the top electrode layer defines a top electrode, and (b) a remaining portion of the insulator layer defines an insulator including the insulator cup and the insulator flange; and

forming a top electrode connection pad conductively connected to the top electrode;

wherein the top electrode is insulated from the upper surface of the bottom electrode cup sidewall by the insulator flange.

9. The method of claim 8 , comprising forming a bottom electrode connection pad in a metal bond pad layer, wherein the bottom electrode connection pad is conductively connected to the bottom electrode cup through the bottom electrode contact.

10. The method of claim 8 , comprising:

forming a bottom electrode base in a lower metal layer,

wherein the dielectric region is formed over the lower metal layer and wherein the tub opening is formed over the bottom electrode base.

11. The method of claim 8 , wherein removing a corner region of the conformal metal layer at a corner defined between the cup-shaped conformal metal layer region and the lateral conformal metal layer region comprises:

forming an oxide layer having an opening over the corner region of the conformal metal layer; and

etching through the opening in the oxide layer to remove the corner region of the conformal metal layer.

12. The method of claim 11 , wherein forming the oxide layer having the opening over the corner region of the conformal metal layer comprises performing a high density plasma (HDP) process including depositing of the oxide layer and sputter etching to remove a corner region of the deposited oxide layer over the corner region of the conformal metal layer thereby forming the opening over the corner region of the conformal metal layer.

13. The method of claim 8 , wherein removing the corner region of the conformal metal layer comprises sputter etching the conformal metal layer.

14. The method of claim 8 , wherein removing upper portions of the top electrode layer, insulator layer, and conformal metal layer comprises performing a planarization process defining a planarized top surface including a top surface of the dielectric region, a top surface of the top electrode layer, and a top surface of the insulator layer.

15. A method, comprising:

forming a lower metal layer including a bottom electrode base and a lower interconnect element;

forming a dielectric region over the lower metal layer;

forming a tub opening, a bottom electrode contact opening, and an interconnect via opening in the dielectric region;

depositing a conformal metal layer over the dielectric region, the deposited conformal metal laver:

(a) extending down into the tub opening to form a cup-shaped conformal metal layer region and a lateral conformal metal layer region extending laterally outwardly from a top of the cup-shaped conformal metal region,

(b) extending down into the bottom electrode contact opening to form a bottom electrode contact connected to the bottom electrode base, and

(c) extending down into the interconnect via opening to form an interconnect via connected to the lower interconnect element; and

removing a corner region of the conformal metal layer at a corner defined between the cup-shaped conformal metal layer region and the lateral conformal metal layer region, wherein a remaining portion of the cup-shaped conformal metal layer region defines a bottom electrode cup including (a) a laterally-extending bottom electrode cup base and (b) a bottom electrode cup sidewall extending upwardly from the laterally-extending bottom electrode cup base;

depositing an insulator layer including (a) an insulator cup in an opening defined by the bottom electrode cup and (b) an insulator flange extending laterally outwardly from the insulator cup and extending laterally over an upper surface of the bottom electrode cup sidewall;

depositing a top electrode layer over the insulator layer and extending into an opening defined by the insulator cup, wherein the top electrode layer includes a top electrode cap region extending over the insulator flange, wherein the insulator flange is arranged between the top electrode cap region and the upper surface of the bottom electrode cup sidewall;

removing upper portions of the top electrode layer, insulator layer, and conformal metal layer, wherein (a) a remaining portion of the top electrode layer defines a top electrode, and (b) a remaining portion of the insulator layer defines an insulator including the insulator cup and the insulator flange; and

forming a top electrode connection pad conductively connected to the top electrode;

wherein the top electrode is insulated from the upper surface of the bottom electrode cup sidewall by the insulator flange.

16. The method of claim 15 , comprising forming an upper metal layer including the top electrode connection pad connected to the top electrode, an upper interconnect element connected to the interconnect via, and a bottom electrode connection pad connected to the bottom electrode contact.

17. The method of claim 15 , wherein removing a corner region of the conformal metal layer at a corner defined between the cup-shaped conformal metal layer region and the lateral conformal metal layer region comprises:

forming an oxide layer having an opening over the corner region of the conformal metal layer; and

etching through the opening in the oxide layer to remove the corner region of the conformal metal layer.

18. The method of claim 17 , wherein forming the oxide layer having the opening over the corner region of the conformal metal layer comprises performing a high density plasma (HDP) process including depositing of the oxide layer and sputter etching to remove a corner region of the deposited oxide layer over the corner region of the conformal metal layer thereby forming the opening over the corner region of the conformal metal layer.

19. The method of claim 15 , wherein removing the corner region of the conformal metal layer comprises sputter etching the conformal metal layer.

20. The method of claim 15 , wherein the tub opening is formed over the bottom electrode base.

Assignments (1)

Continuity (2)

References Cited (30)