Browse Prior Art Database

Contact/Via Metal Intersect Area Calculation in a Layout Editor

IP.com Disclosure Number: IPCOM000172210D
Original Publication Date: 2008-Jul-03
Included in the Prior Art Database: 2008-Jul-03
Document File: 5 page(s) / 41K

Publishing Venue

IBM

Abstract

Disclosed here is a method for calculating intersection area of multiple design levels that may be independently adjusted in size as necessary for calculating varied design ground rules.

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Contact/Via Metal Intersect Area Calculation in a Layout Editor

Layout ground rules continue to increase in number and complexity as semiconductor technology nodes advance to smaller dimensions. An example of one such complex ground rule is the recently created via intersection area ground rule. In the via intersection area example, the following steps are executed to determine what the metal and via intersection area is:

Identify the Mx and M(x+1) intersection in which to calculate the potential Vx intersection area.

Adjust (bias) in size the Mx, Vx, and M(x+1) shapes by an amount determined by manufacturing.

Calculate the (Vx and Mx) and the (Vx and M(x+1)) intersection areas between the biased levels.

    Without the added complexity of the metal and via biasing in step 2, calculating the metal and via intersection area wouldn't be too difficult; however, since the metal levels and vias are being biased, this process can become time consuming and tedious if checking every Mx and M(x+1) intersection with a Vx. To further complicate the calculation process, the same metal level can be biased differently depending on the particular ground rule being checked. The only current solutions to determine this intersection area are to: a) Do all of the calculations in your head/calculator, b) Create the biased shapes in your layout editor and then use the area function in the editor to check the area of the resulting intersections, or c) create a mini-DRC deck to check for compliance, and run it iteratively until all vias pass. None of these solutions are particularly user friendly, and each potentially allows for error. A better solution is needed.

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An example scenario is shown below:

    The metal bias is shown in the first yellow column in the table and the via bias is in the second yellow column. The picture below shows what the biased shapes would look like if they were to be added and how the intersect area would be calculated for this example.

GR (Mx/Vx) Mx width<=0.100 0.013 0.010 (Mx/Vx) Mx 0.100<width<=0.150 0.016 0.010 (Mx/Vx) Mx 0.150<width 0.018 0.010

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A more complicated example:

This disclosure would add functionality to the layout/shapes editor that enables the user to calculate the via intersection area between the biased Mx and Vx and biased M(x+1) and Vx shapes by simply selecting the Mx and M(x+1) levels in the layout/shapes editor and determining some window size to limit the intersect area check.

    This disclosure presents a more efficient way to calculate the intersection area of biased levels. In addition, the user would not need to know any of the bias values. Since the bias and target area values can be different for different types of via inter...