Realization of ultrashallow junctions by plasma immersion ion implantation and laser annealing

Abstract

To achieve the requirements of the 45 nm ITRS technology node and beyond, beamline implantation has reached its limit in terms of low energies. Plasma immersion ion implantation ͑PIII͒ is thus an alternative doping technique for the formation of ultrashallow junctions for source/ drain extension in silicon devices. In this study, the authors present some results obtained on the PIII prototype called PULSION ® designed by the IBS French company. In previous works ͓F. Torregrosa et al., ͑unpublished͒, p. 6͔, it has been shown that this machine offers the possibility to reach ultralow energy implantations and then to obtain implantation depths of only a few nanometers. One of the main issues is then to highly activate these junctions with a limited diffusion of dopants. Wafers have been implanted by PULSION ® with acceleration voltages from 1 to 2 kV at saturation dose, with or without preamorphization implantation ͑PAI͒. Then, they have been annealed by a XeCl excimer laser with a wavelength of 193 nm, with energy densities from 275 to 600 mJ/ cm 2 and several shots. Electrical and physicochemical characterizations such as secondary-ion-mass spectrometry, four-point probe, and optical noncontact measurements were then performed. In this article, the authors investigate the effects of PAI, implantation parameters, and laser fluence on the junction specifications ͑depth, sheet resistance, and leakage current͒.

4H-SiC P⁺N UV Photodiodes : A Comparison between Beam and Plasma Doping Processes

“…We also investigated the technological process giving rise to the dopant introduction into the SiC matrix. The comparison between standard ion implantation and pulsed-Plasma Immersion Ion Implantation (PIII) processes is expected to be fruitful, since PIII technology produced impressive results for Si solar cells in the UV range [1]. To our knowledge, PIII doping has never been carried out in SiC material.…”

Plasma Immersion Ion Implantation Applied To N[sup +]P Junction Realisation In 4H-SiC

“…using N 2 gas. The comparison between these doping techniques is expected to be fruitful, since this last technology produced impressive results for Si solar cells in the UV range [3]. We propose to study the combination of PULSION TM and a proper annealing, which should results in thin n + implanted layers (lower than 20 nm) particularly suitable for UV photon detection.…”

Reduction of surface roughness and defect density by cryogenic implantation of arsenic

“…[1][2][3] In the case of shallow trench isolation (STI) near the trench capacitor, it is difficult to fully recover the crystal defects in an ion-implanted layer, and problems tend to occur, such as an increase in the leakage current of the p/n junction. 4,5) Recovery of the crystal defects in an ion-implanted layer occurs in the process in which point defects and an amorphous state change to defect clusters and dislocations disappear upon annealing. 6,7) Usually, in the ion implantation process, a substrate is placed on the wafer stage of an ion implanter and water is circulated for cooling.…”