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US 7,125,778 B2Granted
Method for fabricating a self-aligning mask
AssigneeInfineon Technologies AG
InventorsDirk Efferenn, Ulrike Grüning Von Schwerin, Hans-Peter Moll, Jörg Radecker, Andreas Wich-Glasen
Life of this patent
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Abstract
A description is given of a method for a selective masking of a structure with a small structure surface with respect to a structure with a larger structure surface. To that end, the structures are filled with a covering layer. The covering layer is formed with a larger thickness above the first structure, which has the larger structure surface, than above the second structure. Afterward, the covering layer is removed by a homogeneous removal method, so that first the structure surface of the second structure is uncovered. A simple self-aligning method for fabricating a mask for uncovering the second structure is thus provided.
Claims14
A method for fabricating a self-aligning mask in a configuration, which comprises the steps of:
- forming, on a semiconductor substrate, a second protrusion structure with a small top surface disposed at a distance from a first protrusion structure with a larger top surface, the first and second protrusion structures having the same height and constituting webs having differently sized cross sections with a trench formed therebetween, the small top surface and the larger top surface constituting the total top surface of the configuration;
- covering the first protrusion structure and the second protrusion structure with a covering layer, a first area of the covering layer covering the second structure protrusion having a smaller thickness than a second area of the covering layer covering the first protrusion structure, the covering step further including:
- forming the covering layer with a sidewall disposed between the first protrusion structure and the second protrusion structure, the sidewall declining from the first protrusion structure towards the second protrusion structure;
- and
- forming the covering layer with a substantially constant thickness above the second protrusion structure;
- and
- removing the covering layer substantially homogeneously until the second protrusion structure being completely uncovered, and the first protrusion structure remaining completely covered by the covering layer.
4 more elements
A method for fabricating a self-aligning mask in a configuration, which comprises the steps of:
- forming, on a semiconductor substrate, a second protrusion structure with a small top surface disposed at a distance from a first protrusion structure with a larger top surface, the first and second protrusion structures having the same height and constituting webs having differently sized cross sections with a trench formed therebetween, the small top surface and the larger top surface constituting the total top surface of the configuration;
- covering the first protrusion structure and the second protrusion structure with a covering layer, a first area of the covering layer covering the second protrusion structure having a smaller thickness than a second area of the covering layer covering the first protrusion structure, the covering step further including:
- forming the covering layer with a sidewall disposed between the first protrusion structure and the second protrusion structure, the sidewall declining from the first protrusion structure towards the second protrusion structure;
- and
- forming the covering layer with a substantially constant thickness above the second protrusion structure;
- and
- removing the covering layer, using an etching process, substantially homogeneously until completely uncovering the second protrusion structure, and the first protrusion structure remaining completely covered by the covering layer.
4 more elements
A method for fabricating a self-aligning mask in a configuration, which comprises the steps of:
- forming, on a semiconductor substrate, a second protrusion structure with a small top surface disposed at a distance from a first protrusion structure with a larger top surface, the first and second protrusion structures having the same height and constituting webs having differently sized cross sections with a trench formed therebetween, the small top surface and the larger top surface constituting the total top surface of the configuration;
- covering the first protrusion structure and the second protrusion structure with a covering layer, a first area of the covering layer covering the second protrusion structure having a smaller thickness than a second area of the covering layer covering the first protrusion structure, the covering step further including:
- forming the covering layer with a sidewall disposed between the first protrusion structure and the second protrusion structure, the sidewall starting at the second area and ending at the first area, causing the sidewall to end before the second protrusion structure, the sidewall declining from the first protrusion structure towards the second structure;
- forming the covering layer with a substantially constant thickness above the second protrusion structure;
- and
- removing the covering layer substantially homogeneously until the second protrusion structure being completely uncovered, and the first protrusion structure remaining completely covered by the covering layer.
3 more elements
A method for fabricating a self-aligning mask in a configuration, which comprises the steps of;
- forming, on a semiconductor substrate, a second protrusion structure with a small top surface disposed at a distance from a first protrusion structure with a larger top surface, the first and second protrusion structures having the same height and constituting webs having differently sized cross sections with a trench formed therebetween, the small top surface and the larger top surface constituting the total top surface of the configuration;
- covering the first protrusion structure and the second protrusion structure with a covering layer, a first area of the covering layer covering the second protrusion structure having a smaller thickness than a second area of the covering layer covering the first protrusion structure, the covering step further including:
- forming the covering layer with a sidewall disposed between the first protrusion structure and the second protrusion structure, the sidewall declining from the first protrusion structure towards the second protrusion structure;
- and
- forming the covering layer with a substantially constant thickness above the second protrusion structure;
- removing the covering layer substantially homogeneously until the second protrusion structure being completely uncovered, and the first protrusion structure remaining completely covered by the covering layer;
- and
- using the covering layer as a mask during further processing of the second protrusion structure.
5 more elements
A method for fabricating a self-aligning mask in a configuration, which comprises the steps of:
- forming, on a semiconductor substrate, a second protrusion structure with a small top surface disposed at a distance from a first protrusion structure with a larger top surface, the first and second protrusion structures having the same height and constituting webs having differently sized cross sections with a trench formed therebetween, the small top surface and the larger top surface constituting the total top surface of the configuration;
- covering the first protrusion structure and the second protrusion structure with a covering layer, a first area of the covering layer covering the second protrusion structure having a smaller thickness than a second area of the covering layer covering the first protrusion structure, the covering step further including:
- forming the covering layer with a sidewall disposed between the first protrusion structure and the second protrusion structure, the sidewall declining from the first protrusion structure towards the second protrusion structure;
- and
- forming the covering layer with a substantially constant thickness above the second protrusion structure;
- removing the covering layer, using an etching process, substantially homogeneously until completely uncovering the second protrusion structure, and the first protrusion structure remaining completely covered by the covering layer;
- and
- using the covering layer as a mask during further processing of the second protrusion structure.
5 more elements
Dependencies are inferred from the claim text.