CHARACTERIZATION OF INGAASP MATERIALS BY ULTRAHIGH INTENSITY POST-IONIZATION MASS-SPECTROMETRY - RELATIVE SENSITIVITY FACTORS FOR ZINC VERSUS BULK CONSTITUENTS
Ml. Wise et al., CHARACTERIZATION OF INGAASP MATERIALS BY ULTRAHIGH INTENSITY POST-IONIZATION MASS-SPECTROMETRY - RELATIVE SENSITIVITY FACTORS FOR ZINC VERSUS BULK CONSTITUENTS, Journal of materials research, 11(2), 1996, pp. 321-324
The first relative sensitivity factors (RSF) for detecting the major a
nd dopant elements of optical materials by ultrahigh intensity post-io
nization (UHIPI) mass spectrometry are determined. The post-ionization
is performed using a single laser wavelength with intensities greater
than 10(14) W/cm(2). Zn-implanted InP and In0.4Ga0.1As0.3P0.2 are use
d to investigate the photoionization of sputtered atoms and molecules.
Under optimal conditions, the UHIPI RSF's for atomic singly charged I
n, Ga, and Zn are nearly equal; that is, the ratio of UHIPI signals is
equal to the concentration ratio. In principle, no standards are need
ed for quantitative analysis. Arsenic and P, with higher ionization po
tentials, are not detected as efficiently as other elements. The detec
ted mass balance is usually group III rich. An entire mass spectrum is
necessary for complete characterization of all elements and adjustmen
t of their RSF's because many sputtered molecules are detected contain
ing the group V elements. Multiply charged species compose about 10% o
f the detected ions.