Temperature and current density distributions in via structures with inhomogenous step coverages

Kirsten Weide; Jens Ullmann

doi:10.1117/12.221445

Abstract

Metallization systems, especially vias are a critical part of any VLSI chip. For the reliability prediction of vias it is important to get information on the temperature- and current density distributions in the metallization structure. Numerical methods like the finite element method FEM, give a better understanding of local heating and current crowding. With a user routine the calculation of the mass flux and mass flux divergences is possible and out of the simulations the weakest link in the structure can be determined. A qualitative comparison of the electromigration resistance between different structures can be done. A via filling with conventional techniques can lead to poor step coverages. An occurrence of shadowing effects during the sputter process of the second metallization can decrease the step coverage in the via as well and can lead to an inhomogeneous step coverage of the metallization material in the via. For a conventional aluminum via structure without barrier layers the current density and temperature distributions as well as the maximum mass flux divergences depending on the step coverage were investigated by finite element simulations. A phenomenological investigation of the influence of different inhomogeneous step coverages in the via on the mass flux divergence was done, and compared with the homogenous normal step coverage. The dependence of the overlap of the second metallization and the via aspect ratio as well as the applied current density from the maximum mass flux divergence will be investigated and the main influences determined.

Citation Download Citation

Kirsten Weide, Kirsten Weide, Jens Ullmann, Jens Ullmann, } "Temperature and current density distributions in via structures with inhomogenous step coverages", Proc. SPIE 2635, Microelectronic Manufacturing Yield, Reliability, and Failure Analysis, (22 September 1995); doi: 10.1117/12.221445; https://doi.org/10.1117/12.221445

ACCESS THE FULL ARTICLE

PERSONAL SIGN IN
Full access may be available with your subscription

Email or Username Forgot your username?

Password Forgot your password?

Show

Remember Email/Username on this computer

Remember Password

No SPIE account? Create an account
or Institutional Sign In via Shibboleth

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available

Members: $14.40

Non-members: $18.00 ADD TO CART

Show All Keywords

Keywords/Phrases

Search In:

Publication Years