Scope and Objectives

1. To develop a low cost micromachining technique to create micro-features in non-conductive materials such as glass
2. To demonstrate void-free copper filling in the etched holes and to use them in 3D Interconnect applications.

Deliverables

1. Electrochemical-discharge micromachining process for semiconductor hard-to-machine-materials such as glass
2. void-free metal-filled vias formed by electrodeposition

Scientific Output

In this project, simultaneous formation of multiple through-holes in hard-to-machine brittle materials such as fused silica, will be demonstrated. Compared to conventional plasma etching, this process will have faster etch rate and lower cost.

Results and outcome till date

A table top ECDM setup is ready which is able to create multiple holes in a 400 micrometer thick fused silica substrate in less than 10 min.

Societal benefit and impact anticipated

Next steps

Filling of the etched holes by copper electrodeposition will be performed. To achieve this, a thin layer of conductive seed layer will be deposited.

Publications and reports

Manuscript submitted to Journal of Material processing Technology. The research outcome has been presented in 8th IEEE-INEC, Malaysia (Invited oral presentation), January 2018.

Patents

Scholars and Project Staff

Aftab Ahmed - Junior research fellow - 10.7.2017 to 14.05.2018
Saleem Khan - Research Associate - 15.06.2017 to 29.12.2017
Swati Rastogi - Project Research assistant -18.04.2017 to 12.07.2017
Swati Rastogi - PhD student - 12.07.2017 to 12.07.2018

Challenges faced

Due to the brittle nature of glass and low thickness ( 400 micrometer), samples are being cracked during the experimental processing. Due to the rough sidewalls, the deposition of continuous 300 nm thin seed layer by sputtering process has not been successful yet. Purchase activities have been affected due to ERP implementation at IIT Bombay.