Correlation between threshold voltage and channel dopant concentration in negative-type metal-oxide-semiconductor field-effect transistors studied by atom probe tomography

Abstract

The correlation between threshold voltage (VT) and channel boron concentration in silicon-based 65 nm node negative-type metal-oxide-semiconductor field-effect transistors was studied by atom probe tomography (APT). VT values were determined for one million transistors in a single chip, and transistors having a ±4σ deviation from the median VT were analyzed using APT. VT and the channel boron concentration were positively correlated. This is consistent with the relationship between the average boron concentration of wafers implanted with different channel doses and the median VT of the million transistors. APT is suitable for the study of dopant-distribution-based device failure mechanisms.

The mechanisms of random trap fluctuation in metal oxide semiconductor field effect transistors

“…1 The phenomenon of device fluctuations becomes increasingly important. One of the most significant issues in the scaling is the threshold voltage (V th ) fluctuation induced by the process or device structure; [1][2][3][4][5][6][7][8][9][10][11] especially the discretedopant in the channel induced random dopant fluctuation (RDF), 2 which is the major source of V th fluctuation. It has been magnified by the scaling of device size (or area) because the electrical characteristics of the device become more and more sensitive to the number of dopants in the channel.…”

Nanoscale Localization of an Atom Probe Tip through Electric Field Mapping

“…1 For this reason, atom probe tomography (APT) has led to remarkable insights in various fields of research. These include the semiconductor industry for logic applications, 2 as well as for batteries, 3 geology, for example, minerals, 4 and biomedical technology, for example, biomaterials, 5,6 among others. APT is based on atom by atom evaporation from a needle-shaped specimen 7 and projecting them onto a two-dimensional detector.…”

Three-Dimensional Characterization of Deuterium Implanted in Silicon Using Atom Probe Tomography

“…Laser-assisted atom probe tomography (APT) is a powerful method of visualizing the position of atoms of specific elements in semiconductor materials with almost atomicscale resolution. [4][5][6][7][8] In principle, APT can detect H atoms, because each element is identified based on its mass-tocharge ratio during time-of-flight measurements. However, during APT analysis, residual H gas adsorbed on the needleshaped specimen becomes field evaporated, leading to a high background signal when attempting to detect the H present in the actual specimen.…”