Electrical Characterization of Ultrashallow Dopant Profiles

Abstract

As devices keep shrinking, the extraction of accurate electrically active dopant profile information becomes a more and more challenging task. The spreading resistance probe (SRP) technique is an attractive tool for electrical characterization, due to its high geometrical depth resolution (in nanometers) and high dynamic range (nine orders of magnitude). In a recent world‐wide round‐robin it has been shown that SRP can generate submicrometer profiles with a 10% accuracy and reproducibility, provided a well‐defined qualification procedure is implemented. In this work we highlight the issues of critical importance for obtaining accurate sub‐ 100 nm carrier depth profiles, as needed for 0.13 and 0.18 μm complementary metal‐oxide‐semiconductor technologies. It is shown that a good agreement can be obtained with the four‐point probe (FPP) sheet resistance and the secondary ion mass spectrometry dopant profile. Examples of today's SRP capabilities are given, illustrating thermal budget management, the influence of preamorphization and a high resolution 10 nm deep boron‐implanted profile. © 2000 The Electrochemical Society. All rights reserved.