Fumitoshi Kawase

Evaluation of Pre-Amorphized Layer Thickness and Interface Quality of High-Dose Shallow Implanted Silicon by Spectroscopic Ellipsometry

We have applied spectroscopic ellipsometry (SE) to measure pre-amorphized layer thickness and interface quality of high-dose shallow implanted silicon as a non-destructive, in line implant monitoring technique. The thickness of pre-amorphized layers formed under various ion implantation conditions was estimated by SE, high resolution Rutherford backscattering spectroscopy, and cross-sectional transmission electron microscopy, and the values from the different techniques were compared. The amorphized layer thickness measured by SE showed larger thickness values than those from other techniques, implying the thickness estimated by SE includes the thickness of the heavily-damaged region near the amorphous-crystal interface where “end of range” defects exist. The thickness of the amorphous layer and heavily-damaged interface layer formed by helium in plasma doping and shallow junction implantation can be monitored by in line SE.

Implant damage evaluation at high energy and low dose ion implantation using white defect of CCD image sensor

The ion implant damage was evaluated using the white defect level of the CCD image sensor in the high energy and the low dose implantation. As a result, it has been understood that beam irradiation time is closely related to the white defect level. Furthermore a little difference at the beam irradiation time influences the level of white defects. It succeeds in the first time evaluation of the implantation damage in high energy and the low dose implantation, and it has been understood to be able to discuss the implantation damage by the similar mechanism of the high dose implantation also in the low dose implantation.

Evaluation of Pre‐Amorphous Layer by Spectroscopic Ellipsometry

We have employed Spectroscopic Ellipsometry (SE) as a measurement technology to non‐destructively and simply measure pre‐amorphous layers made by ion implantation. In this paper, we examine the differences between amorphous film thickness measured by cross‐section‐TEM and SE, aiming at a highly precise evaluation of pre‐amorphous layers created during shallow junction formation at energies below 10 keV. Our data indicates that the amorphous layer thickness measured with SE also includes a portion of the heavily‐damaged crystal near the amorphous‐crystal interface, where EOR defects are located after annealing. For example, thickness of amorphous layers formed by helium in plasma doping tools can be measured with this technology.

Charging Phenomena During Medium Current Ion Implantation of Carbonized Photo-Resist Surface Layers

Charging phenomenon caused by ion implantation into the photo-resist has been evaluated with use of a surface potential measurement tool to clarify the mechanism of burst-like discharge of the accumulated charge in medium current implantation machines. The molecular bond of the photo-resist is cleaved by the kinetic energy of the implanted impurity ions selectively at the portion of the smallest bond energy, and cross-linking develops from this point. Bond breaking and cross-linking is accompanied by out-gassing of hydrogen released by collisions with the dopant atom and recoil cascade atoms. Finally, a carbon-rich layer with low resistance is formed on the photo-resist surface. When arsenic ions are implanted, the degraded layer of low resistance including the carbonization is being formed even under low dose (1 × 1014/cm2 or less) conditions. This is called the medium current charging phenomenon with a current of a few hundred μA. The charges are accumulated on the photo-resist, until the low resistance layer is formed on the surface of the photo-resist. When the induced voltage reaches a critical value, they rush into the open area through the layer. As a result, an explosive local melting of silicon occurs, with the critical value depending on the mask-pattern arrangement.

Evaluation by spectroscopic ellipsometryof Si amorphized layer thickness after implantation and solid phase re-growth at low annealing temperatures

We have applied spectroscopic ellipsometry (SE) to measure amorphized layer thickness after implantation and solid phase re-growth at low annealing temperatures as a non-destructive, in line implant monitoring technique. The SE measurement treats the heavily damaged layer as a part of the amorphized layer. And it is an area very sensitive to the temperature. Therefore, this sensitivity of detecting the heavily damaged layer can be used for monitoring the performance and conditions of individual implanters. In this paper, we examine the thickness of amorphous and heavily-damaged interface layers formed by Clusterion implantation (B10Hx, B16Hy, B36Hz, C5Ha, C7Hb, C16Hc), by helium ions in a plasma doping tool, and single ion implantation. In addition, we report on behavior in the amorphous layer formed by As ion implantation with a heat-treatment of 100–600 degree C.