Browse Prior Art Database

Method for incorporating SOD material in deep-trench STI applications

IP.com Disclosure Number: IPCOM000030150D
Publication Date: 2004-Jul-29
Document File: 4 page(s) / 62K

Publishing Venue

The IP.com Prior Art Database

Abstract

Disclosed is a method for incorporating spin-on dielectric (SOD) material in deep-trench shallow trench isolation (STI) applications. Benefits include improved functionality and improved performance.

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 57% of the total text.

Method for incorporating SOD material in deep-trench STI applications

Disclosed is a method for incorporating spin-on dielectric (SOD) material in deep-trench shallow trench isolation (STI) applications. Benefits include improved functionality and improved performance.

Background

              SOD material fills a deep trench during the spin-coating processes. SOD polymers containing Si-O bonds can become a Si-O structure similar to SiO2 after high temperature annealing (> 600°C) in a steam, O2, or N2 environment. SOD material has less density in the deep trench after the annealing process. The high temperature annealing burns off elements other than Si-O, which leads to the lower density of the SOD material confined to the trench.

      The conventional process for depositing SOD for an STI application is comprised of the following steps (see Figure 1):

1.           Prime the STI depth trench wafers.

2.           Spin coat the SOD to meet the target thickness.

3.           Bake, cure, and anneal.

4.           Perform the chemical mechanical planarization (CMP) process to obtain global planarity.

General description

                            The disclosed method provides a process solution to meet the technical requirements of an STI application in logic and flash devices beyond a 45-nm node, including the following:

•             Gap fill of deep trench

•             High quality oxide

•             High density oxide with less density gradient in the trench

•             Matched buffered hydrofluoric acid (BHF) wet-etch rate between the SOD and Si

Advantages

              The disclosed method provides advantages, including:

•             Improved functionality due to enabling the placement of SOD material in STI deep trenches
•             Improved performance due to improving planarity by multiple coating/cure/annealing steps

•             Improved performance due to enhancing the film density in the vertical direction by multiple coating/cure/annealing steps

•             Improved performance due to improving the BHF wet-etch rate by annealing in the NH3 or N2O environment

 


Detailed description

              The disclosed meth...