Non-destructive techniques applied to the detection of oxygen or metallic precipitates in annealed Cz silicon wafers

Abstract

Non-destructive techniques such as scanning infrared microscopy (SIRM), Fourier transform infrared spectroscopy (FTIR), light-beam-induced current (LBIC) mapping and diffusion length (L n ) measurement techniques, associated with chemical etching were used to detect precipitates in annealed Czochralski (Cz) silicon wafers and to control their interaction with self-interstitials injected into the bulk by phosphorus diffusion or by oxidation. The effect of metallic contamination was also studied by copper diffusion. After nucleation (750 • C) and/or growth (900 • C) annealings phosphorus diffusion at 900 • C for 4 h shrinks the precipitates revealed by SIRM. This shrinkage is due to a marked injection of self-interstitials in the bulk. Annealing of the two-step annealed samples in oxygen produces a similar effect. However, new defects are detected by SIRM, defects which are identified as stacking faults.

Correlation Between Oxygen Precipitation and Extended Defects in Czochralski Silicon: Investigation by Means of Scanning Infrared Microscopy

“…[8][9][10][11][12] Both the principle and application of SIRM have been carefully discussed by Török and Mule'stagno 8 and Booker et al, 9 Booker et al pointed out that SIRM can image particles in silicon materials down to 30 nm in size. 9 To date, SIRM has been widely employed to investigate BMDs in silicon materials.…”

“…9 To date, SIRM has been widely employed to investigate BMDs in silicon materials. [10][11][12][13] It is known that defects are detectable by SIRM because of their strain contrast. The strain of oxygen-precipitation-induced extended defects generally originates from oxygen precipitates, induced dislocations, and stacking faults.…”

Scanning infrared microscopy study of thermal processing induced defects in low resistivity Si wafers

“…Scanning infrared microscopy (SIRM) [10][11][12] and similar techniques such as infrared-light scattering tomography [13][14][15][16][17][18][19][20][21] and infrared light interferometry using an optical precipitate profiler [22][23][24] have been used extensively to study BMD formation in moderately doped Si, but have rarely been applied to study low resistivity Si due to the strong absorption of the probing light beam due to the high free carrier concentration.…”

Scanning infrared microscopy investigation of copper precipitation in cast multicrystalline silicon

“…Scanning Infrared Microscopy (SIRM), as one of powerful tools, have been used to investigate oxygen or metal precipitation in Cz-Si or mc-Si [21][22][23][24][25][26]. Comparing to transmission electron microscopy (TEM), SIRM has the advantage of scanning larger area and not destroying samples.…”