Device manufacturing method and computer program product
AssigneeASML Netherlands B.V.
InventorsRichard Franciscus Van Haren, Maurits Schaar, Ewoud Vreugdenhil
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Abstract
A method of forming features, e.g. contact holes, at a higher density than is possible with conventional lithographic techniques involves forming an array of sacrificial positive features, conformally depositing a sacrificial layer so that negative features are formed interleaved with the positive features, directionally etching the sacrificial layer and removing the sacrificial features. The result is an array of holes at a higher density than the original sacrificial features. These may then be transferred into the underlying substrate using a desired process.
Claims20
A device manufacturing method using a lithographic apparatus, the method comprising:
- printing an array of sacrificial features on a first layer of a substrate, the array of sacrificial features having a first number of features per unit area;
- providing a substantially conformal coating to the array of sacrificial features so as to form a first mask defining a first array of holes, the first array of holes being interleaved with the array of sacrificial features and having the first number of features per unit area;
- removing the sacrificial features so as to form further holes in the first mask that, with the first array of holes, define a second array of holes having a second number of features per unit area that is double the first number of features per unit area;
- providing a second mask that covers a selected part of the second array of holes;
- and
- processing a part of the first layer not covered by the first and second masks.
A device manufacturing method using a lithographic apparatus, the method comprising:
- patterning a first sacrificial hardmask of a substrate using the lithographic apparatus to form a first array of projecting features at a first density;
- substantially conformally depositing a second sacrificial hardmask onto the first array so that an array of recessed features at the first density is formed, the recessed features being interspersed with the projecting features;
- directionally etching the second sacrificial hardmask to reveal the distal surfaces of the projecting features and so that the recessed features become apertures through the second sacrificial hardmask;
- selectively etching away the projecting features to leave apertures in the second sacrificial hardmask;
- and
- etching a first hardmask of the substrate through the apertures in the second sacrificial hardmask.
A device manufacturing method using a lithographic apparatus, the method comprising:
- patterning a first sacrificial hardmask of a substrate using the lithographic apparatus to form an array of projecting lines at a first pitch;
- substantially conformally depositing a second sacrificial hardmask to bury the projecting lines and form a second array of recessed lines interleaved with the buried projecting lines;
- directionally etching the second sacrificial hardmask to reveal the distal surfaces of the buried projecting lines and so that the recessed lines become apertures through the second sacrificial hardmask;
- selectively etching away the buried projecting lines to leave apertures in the second sacrificial hardmask;
- masking at least the ends of one or more of the apertures in the second sacrificial mask;
- and
- etching the substrate through the apertures in the second sacrificial hardmask.
A computer program product comprising program code to control a lithographic cluster including a lithographic apparatus to perform a device manufacturing method comprising:
- printing an array of sacrificial features at a first density on a first layer of a substrate;
- providing a substantially conformal coating to the array of sacrificial features so as to form a first mask defining a first array of apertures at the first density, the first array of apertures being interleaved with the array of sacrificial features;
- removing the sacrificial features so as to form further apertures in the first mask that, with the first array of apertures, define a second array of apertures at a second density that is double the first density;
- and
- processing a part of the first layer not covered by the first mask.
Dependencies are inferred from the claim text.