Interpretation of Donor Activation in Boron and Argon Implanted Self-Aligned Bottom-Gate IGZO TFTs

Abstract

This work provides an interpretation of donor activation in self-aligned bottom-gate (SA-BG) Indium-Gallium-Zinc Oxide (IGZO) TFTs with ion-implantation of boron (11B+) and argon (40Ar+) species as the source/drain treatment. Device fabrication strategies that switched the order of ion implantation and passivation annealing processes were investigated. Hypotheses in the mechanisms involved with donor activation have been developed from observed similarities and differences in the electrical operation of SA-BG TFTs fabricated using both implant-last and anneal-last approaches. Results suggest a defect-induced mechanism is responsible for donor behavior associated with argon implantation, whereas donor behavior associated with boron is attributed to the formation of an electrically active donor species involving chemical bonding. A detailed discussion on developed arguments arrived at through analysis of TFT electrical characteristics is presented. Materials analysis in support of the interpretation and associated arguments is in progress.

A Kinetic Model for the Generation and Annihilation of Thermally Induced Carrier Donors in a Semiconducting Metal‐Oxide Thin Film

“…It is well known that there are extrinsic and intrinsic carrier donors in an MO semiconductor. Extrinsic carrier donors are intentionally or unintentionally introduced impurities, such as boron, [ 21 ] fluorine, [ 22 ] magnesium, [ 23 ] phosphorus, [ 24 ] arsenic [ 25 ] or hydrogen. [ 26 ] Intrinsic carrier donors are derived from structural defects, such as the interstitials of metal ions [ 27,28 ] or oxygen deficiency.…”

Performance Improvement of Self-Aligned Coplanar Amorphous Indium–Gallium–Zinc Oxide Thin-Film Transistors by Boron Implantation

“…In this study, we examined the electrical characteristics and stability properties of SA coplanar a-IGZO TFTs by B doping of the n + region using an ion implantation method. Although there have been studies on B implantation in a-IGZO TFTs, ,− we systematically analyzed the effects of the precisely controlled distribution of B in IGZO thin films on the electrical and reliability characteristics of IGZO thin films. Electrical, chemical, and physical characteristics were evaluated to gain insight into the conduction mechanism of B implantation.…”