| 摘要 |
An ion implantation device and a method of manufacturing a semiconductor device is described, wherein ionized boron hydride molecular clusters are implanted to form P-type transistor structures. For example, in the fabrication of Complementary Metal-Oxide Semiconductor (CMOS) devices, the clusters are implanted to provide P- type doping for Source and Drain structures and for Polygates; these doping steps are critical to the formation of PMOS transistors. The molecular cluster ions have the chemical form BnHx+ and BnHx-, where 10<n<100 and 0<=x<=n+4. The use of such boron hydride clusters results in a dramatic increase in wafer throughput, as well as improved device yields through the reduction of wafer charging. Thus, this technology significantly reduces manufacturing costs relative to prior implantation techniques. A method of manufacturing a semiconductor device is further described, comprising the steps of: providing a supply of molecules containing a plurality of dopant atoms into an ionization chamber, ionizing said molecules into dopant cluster ions, extracting and accelerating the dopant cluster ions with an electric field, selecting the desired cluster ions by mass analysis, modifying the final implant energy of the cluster ion through post-analysis ion optics, and implanting the dopant cluster ions into a semiconductor substrate. In general, dopant molecules contain n dopant atoms, where n is an integer number greater than 10. This method enables increasing the dopant dose rate to n times the implantation current with an equivalent per dopant atom energy of 1/n times the cluster implantation energy, while reducing the charge per dopant atom by the factor n. This is an effective method for making shallow transistor junctions, where it is desired to implant with a low energy per dopant atom.
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