Ion Implantation of Silicon: Ii. Electrical Evaluation Using Hall-Effect Measurements

Abstract

Hall-effect and sheet-resistivity measurements have been made on silicon samples implanted with Sb, Ga, and As ions at energies between 20 and 75 keV. These measurements determine the weighted average of the number Ns of carriers/cm2 and the carrier mobility in the implanted layer. A combination of Hall measurements and layer-removal techniques was used in some cases to obtain a more accurate value of the number of carriers/cm2 and the depth dependence of the carrier concentration and mobility.For Sb implantations both temperature and dose affect the anneal characteristics. Silicon samples implanted with Sb at room temperature exhibited n-type behavior following anneal at 300 °C, with little increase in Ns up to about 550 °C anneal temperatures. A 600 °C 10-minute anneal produced an order-of-magnitude increase in Ns. This change is associated with reordering of the amorphous layer created during room-temperature implantations. This amorphous layer is not produced in implantations made at temperatures above 450 °C. In low-dose (<1014/cm2) Sb implantations at 500 °C, Ns increased by a factor of 2 to 3 during anneal to 800 °C. In high-dose (>5 × 1014/cm2) Sb implantations, the carrier concentration exceeded the limit set by thermal equilibrium solubility of Sb in silicon. Under these conditions, annealing caused a decrease in Ns toward the value associated with the solubility.Such supersaturation effects were not observed in Ga and As implantations at 500 °C. Annealing to temperatures of 800–900 °C produced a one-to-two order-of-magnitude increase in the number of carriers/cm2. In Ga implantations annealed to 800–900 °C, the number of carriers/cm2 increased approximately linearly with increasing dose and then leveled off at a value near that expected from thermal solubility.The Rutherford-scattering data in the preceding paper indicates that the difference in implantation behavior between various ion species is due to differences in the relative number of ions on substitutional sites.

Hall Effect measurements on p-n-p InP structures

“…For H4, the effective concentration value N s is 3.13 x 10 18 cm −3 whereas N d is 4.18 x 10 18 cm −3 . N s is therefore about 75 % of N d , a figure similar to that found by Mayer [18] in implanted layers of silicon. For all of the p-type layers which were sectioned and probed at successive depths, the transition from p-to n-type material was found to correspond fairly closely (∼ 3 µm) to the position of the p-n junction as shown in the staining procedure.…”

Formation of silver nanoparticles in silicon by metal vapor vacuum arc ion implantation

“…1(b), which is approximately 33% in volume fraction for the supersaturated solid solution of Ag in Si. The dosage-threshold for amorphization of Si by Ag-ions, expected to be close to that of Sb, is estimated to be on order of 10 14 Ag-atoms/cm 2 as reported in the literature [8,9].…”

“…It contains most of the Ag NPs thus formed. The sharp boundary between the amorphized region and the underlying defect-laden region, though largely still crystalline, manifests that the dosage threshold of irradiation-induced amorphization [8,9] has been reached or surpassed.…”

“…Diffuse multiple scatterings of photoelectrons in the nano-scale Ag particles were later found to be responsible for the enhanced efficiency of photoemission [5][6][7] and hence the increased sensitivity of photodetection. There have been continuing interests in similar device concepts that exploit the nano-composites of metal-semiconductor or metal-insulator systems [8,9] in the quest for better quantum efficiency and more extended wavelength-limits for photovoltaic applications. In comparison with the complex Ag-O-Cs material system, binary eutectic system of Ag-Si is simpler and may offer some advantages over its more complicated counterparts of more elements, if the viability of integrated microelectronic fabrication is a concern.…”

Experimental Evaluation of High Energy Ion Implantation Gradients for Possible Fabrication of a Transistor Pedestal Collector

“…Depth profiles of carrier concentration and carrier mobility were accomplished by using these measurements in conjunction with anodic oxidation and HF layer removal techniques as outlined [4] by Mayer et al The details of the experimental procedure have been reported [5]. Annealing was conducted in a nitrogen atmosphere.…”