Self-aligned spacers and method forming same
First Claim
1. A method comprising:
- forming a first inter-layer dielectric overlying a source/drain region of a transistor;
forming a first source/drain contact opening in the first inter-layer dielectric;
forming a first source/drain contact spacer in the first source/drain contact opening;
filling a remaining portion of the first source/drain contact opening to form a first source/drain contact plug electrically coupling to the source/drain region;
forming a first etch stop layer over and in contact with the first inter-layer dielectric, a gate spacer of the transistor and the first source/drain contact plug;
forming a second inter-layer dielectric overlying and contacting the first etch stop layer;
forming a second source/drain contact plug in the second inter-layer dielectric, wherein the second source/drain contact plug is over and contacting the first source/drain contact plug;
forming a third inter-layer dielectric overlying the second inter-layer dielectric;
etching the second inter-layer dielectric and the third inter-layer dielectric to form a gate contact opening, with a gate electrode of the transistor exposed through the gate contact opening;
etching the third inter-layer dielectric, wherein a second source/drain contact opening is formed to reveal the second source/drain contact plug;
simultaneously forming a gate contact spacer and a source/drain contact spacer extending into the gate contact opening and the second source/drain contact opening, respectively, wherein the gate contact spacer comprises an edge contacting an edge of the gate spacer to form a vertical interface; and
filling remaining portions of the gate contact opening and the second source/drain contact opening simultaneously to form a gate contact plug and a third source/drain contact plug, respectively.
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Accused Products
Abstract
A method includes forming a bottom source/drain contact plug in a bottom inter-layer dielectric. The bottom source/drain contact plug is electrically coupled to a source/drain region of a transistor. The method further includes forming an inter-layer dielectric overlying the bottom source/drain contact plug. A source/drain contact opening is formed in the inter-layer dielectric, with the bottom source/drain contact plug exposed through the source/drain contact opening. A dielectric spacer layer is formed to have a first portion extending into the source/drain contact opening and a second portion over the inter-layer dielectric. An anisotropic etching is performed on the dielectric spacer layer, and a remaining vertical portion of the dielectric spacer layer forms a source/drain contact spacer. The remaining portion of the source/drain contact opening is filled to form an upper source/drain contact plug.
61 Citations
20 Claims
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1. A method comprising:
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forming a first inter-layer dielectric overlying a source/drain region of a transistor; forming a first source/drain contact opening in the first inter-layer dielectric; forming a first source/drain contact spacer in the first source/drain contact opening; filling a remaining portion of the first source/drain contact opening to form a first source/drain contact plug electrically coupling to the source/drain region; forming a first etch stop layer over and in contact with the first inter-layer dielectric, a gate spacer of the transistor and the first source/drain contact plug; forming a second inter-layer dielectric overlying and contacting the first etch stop layer; forming a second source/drain contact plug in the second inter-layer dielectric, wherein the second source/drain contact plug is over and contacting the first source/drain contact plug; forming a third inter-layer dielectric overlying the second inter-layer dielectric; etching the second inter-layer dielectric and the third inter-layer dielectric to form a gate contact opening, with a gate electrode of the transistor exposed through the gate contact opening; etching the third inter-layer dielectric, wherein a second source/drain contact opening is formed to reveal the second source/drain contact plug; simultaneously forming a gate contact spacer and a source/drain contact spacer extending into the gate contact opening and the second source/drain contact opening, respectively, wherein the gate contact spacer comprises an edge contacting an edge of the gate spacer to form a vertical interface; and filling remaining portions of the gate contact opening and the second source/drain contact opening simultaneously to form a gate contact plug and a third source/drain contact plug, respectively. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A method comprising:
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forming a first source/drain contact plug in a first inter-layer dielectric, wherein the first source/drain contact plug is electrically coupled to a source/drain region of a transistor; forming a second inter-layer dielectric overlying the first inter-layer dielectric; forming a second source/drain contact plug in the second inter-layer dielectric; forming a third inter-layer dielectric overlying the second inter-layer dielectric; etching the second inter-layer dielectric and the third inter-layer dielectric to form a gate contact opening, wherein a gate electrode of the transistor is exposed to the gate contact opening; after the second inter-layer dielectric and the third inter-layer dielectric are etched to form the gate contact opening, etching a hard mask between gate spacers of the transistor to extend the gate contact opening between the gate spacers; filling the gate contact opening with a photo resist; removing the photo resist from the gate contact opening; forming a gate contact spacer in the gate contact opening, wherein the gate contact spacer penetrates through the second inter-layer dielectric and the third inter-layer dielectric; and forming a gate contact plug in the gate contact opening, wherein the gate contact plug is encircled by the gate contact spacer. - View Dependent Claims (10, 11, 12, 13, 14, 15)
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16. A method comprising:
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forming a replacement gate stack between two gate spacers, wherein the replacement gate stack and the two gate spacers are in a first Inter-Layer Dielectric (ILD); forming a hard mask overlapping the replacement gate stack, wherein the hard mask is also between the two gate spacers; forming a source/drain region on a side of the replacement gate stack; forming a second ILD over the first ILD; forming a first source/drain contact plug and a second source/drain contact plug in the first ILD and the second ILD, respectively; forming a third ILD over the second ILD; forming a source/drain contact opening in the third ILD; forming a gate contact opening in the third ILD and the second ILD; and forming a source/drain contact spacer and a gate contact spacer in the source/drain contact opening and the gate contact opening, respectively, wherein the source/drain contact spacer and the gate contact spacer are formed of a same dielectric material, and wherein the gate contact spacer contacts one of the two gate spacers. - View Dependent Claims (17, 18, 19, 20)
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Specification