PULSED ION-BEAM SURFACE-ANALYSIS AS A MEANS OF IN-SITU REAL-TIME ANALYSIS OF THIN-FILMS DURING GROWTH

Low-energy (5-15 keV) pulsed ion beam surface analysis comprises sever al different surface spectroscopies which possess the ability to provi de a remarkably wide range of information directly relevant to the gro wth of single and multicomponent semiconductor, metal and metal-oxide thin films and layered structures. Ion beam methods have not however, been widely used as an in situ monitor of thin film growth because exi sting commercial instrumentation causes excessive film damage, physica lly conflicts with the deposition equipment, and requires a chamber pr essure approximately 10(-7)-10(-8) Torr, i.e., much lower than that as sociated with most deposition processes (greater-than-or-equal-to 10(- 4) Torr). We have developed time-of-flight ion scattering and recoil s pectroscopy (TOF-SARS) as a nondestructive, in situ, real-time probe o f thin film composition and structure which does not physically interf ere with the deposition process. Several TOF-SARS implementations are exceptionally surface specific, yet in a properly designed system can yield high-resolution data at ambient pressures well in excess of 10 m Torr (4-6 orders of magnitude higher than conventional surface analyti c methods). Because of the exceptional surface specificity of these me thods, TOF-SARS is ideally suited as a means of studying ultrathin lay ers and atomically abrupt interfaces. TOF-SARS instrumentation designe d specifically for use as an in situ, real-time monitor of growth proc esses for single and multicomponent thin films and layered structures is described here. Representative data are shown for in situ analysis of Pb and Zr layers at room temperature and high vacuum, as well as un der conditions appropriate to the growth of Pb(ZrxTi1-x)O3 (PZT) perov skite films on MgO and RuO2 substrates.