Integrated circuits with self aligned contact structures for improved windows and fabrication methods
Devices and methods for forming semiconductor devices with self aligned contacts for improved process windows are provided. One method includes, for instance: obtaining a wafer with at least two gates, forming partial spacers adjacent to the at least two gates, and forming at least one contact on the wafer. One intermediate semiconductor device includes, for instance: a wafer with an isolation region, at least two gates disposed on the isolation region, at least one source region disposed on the isolation region, at least one drain region disposed on the isolation region, and at least one contact positioned between the at least two gates, wherein a first portion of the at least one contact engages the at least one source region or the at least one drain region and a second portion of the at least one contact extends above a top surface of the at least two gates.
1. A method comprising:
obtaining a wafer with at least two gates;
forming partial spacers adjacent to the at least two gates, wherein forming the partial spacers comprises:
etching into an oxide layer between the at least two gates;
depositing a spacer layer over the wafer; and
etching the spacer layer to form the partial spacers; and
forming at least one contact on the wafer;
depositing a second oxide layer over the wafer after forming the partial spacers; and
performing planarization to the second oxide layer.
2. The method of claim 1 , wherein forming the at least one contact comprises:
depositing an interlayer dielectric layer over the wafer;
applying a photoresist layer;
patterning the photoresist layer;
etching into the interlayer dielectric layer, the second oxide layer, and the oxide layer between the partial spacers to form at least one cavity;
removing the photoresist layer;
depositing at least one contact material over the wafer and into the at least one cavity; and
performing planarization to the wafer to remove excess contact material to form the at least one contact.
3. The method of claim 2 , further comprising:
etching to remove the partial spacers before depositing the at least one contact material.
4. The method of claim 1 , further comprising:
forming a self-aligned contact over each of the at least two gates.
5. A method comprising:
obtaining a wafer with at least two gates;
forming partial spacers adjacent to the at least two gates, wherein forming the partial spacers comprises:
etching into an oxide layer between the at least two gates;
depositing a spacer layer over the wafer; and
etching the spacer layer to form the partial spacers; and
forming at least one contact on the wafer, wherein forming the at least one contact comprises:
forming at least one cavity between the partial spacers;
depositing at least one contact material over the wafer and into the at least one cavity;
performing planarization to the wafer to remove excess contact material to form the at least one contact;
depositing a second oxide layer over the wafer after planarization of the contact material;
patterning the second oxide laver;
depositing a second layer of the at least one contact material; and
performing planarization to the wafer to remove excess contact material to form the at least one contact.
6. The method of claim 5 , wherein forming the at least one contact further comprises:
etching to remove the partial spacers before depositing the at least one contact material.
7. The method of claim 5 , wherein forming the at least one cavity between the partial spacers comprises:
etching directly into the interlayer dielectric layer and the oxide layer to form the at least one cavity.
8. The method of claim 5 , wherein forming the at least one cavity between the partial spacers comprises:
applying a photoresist layer over the wafer;
patterning the photoresist layer;
etching into the interlayer dielectric layer and the oxide layer to form the at least one cavity.
9. The method of claim 5 , wherein forming the at least one cavity between the partial spacers comprises:
depositing a second oxide layer over the wafer;
performing planarization to the second oxide layer;
applying a photoresist layer over the wafer;
patterning the photoresist layer; and
etching into the interlayer dielectric layer and the oxide layer to form the at least one cavity.