Browse Prior Art Database

Smart Anchoring to improve process margin

IP.com Disclosure Number: IPCOM000240260D
Publication Date: 2015-Jan-16
Document File: 4 page(s) / 255K

Publishing Venue

The IP.com Prior Art Database

Abstract

Disclosed is a method for smart anchoring to improve process margin in which the Chemical Mechanical Planarization (CMP) topography simulation is received as input for the selection of anchor structures.

This text was extracted from a Microsoft Word document.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 54% of the total text.

Title

Smart Anchoring to improve process margin

Abstract

Disclosed is a method for smart anchoring to improve process margin in which the Chemical Mechanical Planarization (CMP) topography simulation is received as input for the selection of anchor structures.

Problem

Focus centering in lithography is critical due to various factors in the present technology nodes that lead to narrow overall process window conditions.  One of the major delimiters is the focus variations induced by uneven topography left from CMP.  Currently, focus centering is done on a spatially equal selection of anchor structures placed within the chip (and frame).

A method is needed to provide better initial focus centering to solve (or at least reduce) process marginality problems for lithography due to CMP topography.

Solution/Novel Contribution

The novel contribution is a method for smart anchoring to improve process margin.  The novel method receives the CMP topography simulation as input for the selection of anchor structures.

Focus centering in lithography is more accurate using this method when large CMP topography variations are pre-selected across the dies/chiplets of the products.  Since this method is set well in advance (for proto-lots), better yield achievement is achieved during new product introductions.

Figure 1: A real example of a Focus-Exposure Matrix (FEM) wafer, exhibiting bad focus centering (a) vs. better focus centering (b) after implementation of the novel method.

Method/Process

Currentl...