Implantation, process

The shallow penetration of ion implantation would in itself make it appear useless as a technique for engineering appHcations however, there are several situations involving both physical and chemical properties in which the effect of the implanted ion persists to depths fat greater than the initial implantation range. The thickness of the modified zone can also be extended by combining ion implantation with a deposition technique or if deposition occurs spontaneously during the ion implantation process. In addition, ion implantation at elevated temperatures, but below temperatures at which degradation of mechanical properties could occur, has been shown to increase the penetration depths substantially (5). 

Figure 6 shows a two-dimensional schematic view of an individual ion s path in the ion implantation process as it comes to rest in a material. The ion does not travel in a straight path to its final position due to elastic collisions with target atoms. The actual integrated distance traveled by the ion is called the range, R The ion s net penetration into the material, measured along the vector of the ion s incident trajectory, which is perpendicular to the... 

The United States leads in basic research related to implantation processes and in the development of equipment for conventional applications of ion implantation. Japan appears to have the initiative in the development of equipment for ion microbeam technologies. 

Here we will report measurements on the heat capacity of two NTD Ge 34B wafers, one non-metallized (only doped and annealed) and the other metallized (by B+ implantation and Au deposition). The comparison of data obtained from the non-metallized NTD Ge wafer and from the wafer with electrical contacts revealed an excess heat capacity, which can be attributed to the implantation process with B ions [44],... 

Ion implantation appears as the only feasible method to accomplish selective area doping of SiC in planar device technology. As described in this chapter, substantial progress has been made during recent years but several fundamental issues and technology barriers remain before the implantation process is fully developed and can be truly implemented in SiC device processing. Eor instance, mesa-etched p n-diodes... 

Lulli, G., et al., The Monte Carlo Binary Collision Approximation Applied to the Simulation of the Ion Implantation Process in Single-Crystal SiC High-Dose Effects, Mater. Sci. Forum, Vol. 335-356, 2001, pp. 599-602. 

In recent years, the electronics industry has made increasing use of ion imptamaiion as a method of doping semiconductors. Since rhe number of ions implanted is determined hy the charge transferred to the substrate and Iheir depth distribution hy the incident energy, ion implantation has improved the controllability and reproducibility of certain semiconductor device processing operations. Also, ion implantation processes do not... 

Fig. 9. A Schottky barrier gate used in the metal-semiconductor field-effect transistor (MESFET) in AT T gallium arsenide microchips. The tiny gate is only one micrometer wide (1/25,400 inch). The gate electrode is deposited before the ion-implantation process so that the gate material will shade the channel under it from the ion rain that doses the exposed material. (AT T Technology)...

Ti ion-implanted titanium oxides exhibited no shift, showing that such a shift is not caused by the high energy implantation process itself, but to some interaction of the transition metal ions with the titanium oxide catalyst. As can be seen in Fig. 10-1 ((b)—(d)), the absorption band of the Cr ion-implanted titanium oxide shifts smoothly to visible light regions, the extent of the red shift depending on the amount and type of metal ions implanted, with the absorption maximum and... 

Typically, a source gas such as boron trifluoride [7637-07-2], BF3, is exposed to an ion source that causes the gas to ionize. An analyzer discriminates between all the ionic particles using a magnetic field that can select particles having the correct mass-to-charge ratio to pass through the analyzer to an acceleration tube. The ions are accelerated in the tube and collimated into a beam that is scanned over the substrate wafer. The three primary parameters of any implantation process are the type of dopant species, the accelerating energy used for implantation, and the dose of the source gas. The dose is the total number of ions that enter the wafer. Dose, ( ), can be calculated... 

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