Page 128 - Semiconductor Manufacturing Handbook

Geng(SMH)_CH10.qxd 04/04/2005 19:46 Page 10.1

Source: SEMICONDUCTOR MANUFACTURING HANDBOOK

CHAPTER 10

ION IMPLANTATION AND RAPID
THERMAL PROCESSING

Michael Graf
Axcelis Technologies Inc.
Beverly, Massachusetts

10.1 OVERVIEW

Modern ion implantation forms a cornerstone of advanced complementary metal oxide semicon-
ductor (CMOS) processing. By providing significant flexibility in the selection of dopant species
and precision in the amount and spatial placement of these dopants, ion implanters help enable
the aggressive scaling of advanced CMOS devices from one generation to the next. The manu-
facture of modern integrated devices can require up to dozens of individual ion implantation
steps covering a wide range of doses and subsurface profile depths. The tools to enable these
demands have evolved over a number of decades, but still retain surprising commonality with
their original embodiments.

10.1.1 Basic Principles
Ion implantation has historically been divided into several distinct types of processes, each serviced
by a distinct type of tool engineered to provide a solution for a specific segment of the application
space. Traditionally, these segments have been referred to as high current, high energy, and medium
current, and can be characterized mainly by the dose and the energy of implanted ions used for appli-
cations in each segment. Shown in Fig. 10.1 is a typical dose-energy map that roughly highlights
these major segments.
16
−2
13
High-current implantation primarily delivers doses in the range of 10 to 10 cm at energies
no higher than about 100 keV but as low as 0.2 keV. The most common applications for which high-
current implanters are used include:
• Source/drain contact formation
• Source/drain extension formation
• Polysilicon doping
• Preamorphization
• Bonded wafer splitting

Downloaded from Digital Engineering Library @ McGraw-Hill (www.digitalengineeringlibrary.com) 10.1
Copyright © 2004 The McGraw-Hill Companies. All rights reserved.
Any use is subject to the Terms of Use as given at the website.