Additional Process Techniques in Microfabrication

Overview

This course provides an introduction to some additional process techniques critical to the microfabrication process flow. Learners will be able to explain how the electroplating process produces coatings on devices, including some specific considerations for magnetic materials. Device packaging, testing, and other back-end-of-line (BEOL) processes will be introduced and discussed. This course is part of the Semiconductor and MEMS Fabrication Specialization. It is recommended that learners take the previous courses of the Specialization prior to this course. Please disregard module numbers because the content has been reorganized to improve comprehension and flow of the specialization.

Syllabus

Introduction to Electroplating

In this module, we present some of the fundamental principles and considerations for the electrodeposition of materials. You will learn some basic electrochemical principles that are foundational to understanding the electroplating process. We will discuss some of the physical phenomena and bath constituents that impact electrodeposition and how they can be controlled. Lastly, we will walk through the process flow for copper electroplating commonly used in the semiconductor industry.

Electroplating for Magnetic Materials

Unique considerations for the electrodeposition of magnetic materials are discussed. The deposition of magnetic materials is one of the key drivers to innovation and development of electrodeposition in the microfabrication ecosystem. You will learn some relevant magnetic properties and the distinction between hard and soft magnetic materials. We then discuss key alloy systems commonly deposited for these applications and learn how to work with ternary diagrams. The module concludes with deposition techniques and parameters of interest for magnetic materials and discussion on the continued work to develop and improve upon this unique fabrication process.

Back-end processes (BEOL)

This module introduces the Back End of the Line assembly process steps of wafer test, chip singulation, chip packaging, and final package test. Test types during various phases of process development and different test variables for IC and MEMS device types are presented. Chip packaging technology evolution over the years is covered. Product requirements drive the IC chip packaging technology development. A few types of MEMS device packaging are touched upon.

Metrology

This module covers metrology, inspection, and characterization of micro device chips like MEMS, and IC chips. Metrology is presented from the production flow perspective where quality control, yield, and cycle time are critical. Working principle and metrology equipment architecture are presented for the mostly widely used tools like high magnification optical microscopes and SEMs.