Method of aligning substrate-scale mask with substrate

Patent metadata

Field	Value
Publication number	US-9490154-B2
Application number	US-201514598061-A
Country	US
Kind code	B2
Filing date	Jan 15, 2015
Priority date	Jan 15, 2015
Publication date	Nov 8, 2016
Grant date	Nov 8, 2016

Abstract

Methods and systems for alignment of substrate-scale masks are described. The alignment methods presented may improve the uniformity and repeatability of processes which are impacted by the relative lateral position of a substrate-scale mask and a substrate. The methods involve measuring the “overhang” of the substrate at multiple locations around the periphery of the substrate-scale mask. Based on the measurements, the relative position of the substrate relative to the substrate-scale mask is modified by adjustment of the substrate and/or mask position. The adjustment of the relative position is made in one adjustment in embodiments. A feature of hardware and methods involves the capability of making measurements and adjustments while a substrate processing system is fully assembled and possibly under vacuum.

First claim

The invention claimed is:

1. A method of etching a substrate, the method comprising:
placing the substrate in a substrate processing region of a substrate processing chamber;
evacuating the substrate processing region to a pressure of less than 80 Torr;
moving a substrate-scale mask towards the substrate; wherein the substrate-scale mask and the substrate are parallel, and wherein the substrate-scale mask is smaller than the substrate in two or more lateral dimensions;
making a first measurement of a first overhang of the substrate beyond an edge of the substrate-scale mask at a first location around a perimeter of the substrate-scale mask;
making a second measurement of a second overhang of the substrate beyond an edge of the substrate-scale mask at a second location around the perimeter; and
moving the substrate laterally such that the substrate-scale mask and the substrate are laterally aligned, wherein an amount of motion is calculated from the first measurement of the first overhang and the second measurement of the second overhang,
wherein the substrate-scale mask is approximately the same dimension as the substrate.

2. The method of claim 1 further comprising making a third measurement of a third overhang of the substrate beyond the edge of the substrate-scale mask at a third location around the perimeter and using the third measurement, the second measurement and the first measurement to determine the amount of motion.

3. The method of claim 1 wherein a distance from the substrate-scale mask to the substrate is less than 50 μm.

4. The method of claim 1 wherein each of the substrate and the substrate-scale mask are circular and a diameter of the substrate-scale mask is smaller than a diameter of the substrate.

5. The method of claim 1 wherein each of the substrate and the substrate-scale mask are rectangular and a major dimension of the substrate-scale mask is less than a major dimension of the substrate and a minor dimension of the substrate-scale mask is less than a minor dimension of the substrate.

6. The method of claim 1 wherein each of the first overhang and the second overhang are less than 3 mm following the operation of moving the substrate laterally.

7. A method of etching a substrate, the method comprising:
placing the substrate in a substrate processing region of a substrate processing chamber;
evacuating the substrate processing region to a pressure of less than 80 Torr;
moving a substrate-scale mask towards the substrate; wherein the substrate-scale mask and the substrate are parallel and a spacing between the substrate-scale mask and the substrate is less than 100 μm, and wherein the substrate-scale mask and the substrate are both circular and the substrate-scale mask has a diameter which is less than a diameter of the substrate;
making a first measurement of a first overhang of the substrate beyond an edge of the substrate-scale mask at a first location around a circumference of the substrate-scale mask;
making a second measurement of a second overhang of the substrate beyond an edge of the substrate-scale mask at a second location around the circumference;
moving the substrate laterally such that the substrate-scale mask and the substrate are essentially concentric, wherein an amount of motion is calculated from the first measurement of the first overhang and the second measurement of the second overhang; and
preferentially etching a film from a circumference of the substrate by flowing an etching precursor to the circumference of the substrate.

8. The method of claim 7 wherein the first location and the second location are separated by ninety degrees around the circumference of the substrate-scale mask.

Assignees

• Applied Materials Inc

Inventors

• Ravid Abraham
• Egan Todd
• Connors Paul
• Starik Sergey
• Balasubramanian Ganesh

Classifications

• H10P76/00

  Manufacture or treatment of masks on semiconductor bodies, e.g. by lithography or photolithography · CPC title

• H10P74/23

  characterised by multiple measurements, corrections, marking or sorting processes · CPC title

• H10P72/0418

  for etching · CPC title

• H10P50/691

  for Group V materials or Group III-V materials · CPC title

• H10W46/00

  Marks applied to devices, e.g. for alignment or identification · CPC title