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A Native BEOL Resistor

IP.com Disclosure Number: IPCOM000235765D
Publication Date: 2014-Mar-25
Document File: 3 page(s) / 49K

Publishing Venue

The IP.com Prior Art Database

Abstract

Disclosed is a new native Back End of Line (BEOL) resistor that provides higher current carrying capability and better joule heating management.

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A Native BEOL Resistor

As technology scales, the resistor is pushed upward to the Back End of Line (BEOL). The current planner thin film resistor in the BEOL has a severe limitation of current carrying and joule heating.

The novel contribution is a new native BEOL resistor that provides higher current carrying capability and better joule heating management. The approach uses Mx+1/VxBAR liner as the body of the BEOL resistor, and builds (Mx+1/VxBAR_RES)/Mx arrays to make the resistor not only easy to trim, but also better for current and joule heating management. Thus, the method described herein provides:


 A structure to form native BEOL resistors


 Layouts for easy resistor trimming


 Layouts for higher current density carrying using metal stack cooling columns


 Methods to fabricate these resistors

The main idea comprises:

1. Using the VxBAR/Mx+1 liner (bottom and sidewall) as the resistor A. Blocking the Cu fill on those segments targeted as resistor, called VxBAR_RES

    B. Low TCR
2. Build arrays of Mx/VxBAR_RES, using short Mx links (no electromigration (EM)

  concerns from joule heating) can trim the array to get the desired resistance
3. Insert dummy Mx+1 and Mx lines in the array to mitigate joule heating issues

Figure 1: Main idea

Figure 2: Process details

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Figure 3: Layout example #1

Figure 4: Layout example #2

Advantages of using arrays:


 Can be trimmed

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 Higher current carrying capability


 Less joule heating

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