Distribution and properties of oxide precipitates in annealed nitrogen doped 300 mm Si wafers

Abstract

Spatial distribution and properties of oxide were examined in 300 mm nitrogen (N) doped CZ-Si. Experimentally grown materials with N ranging from ∼ 10 13 cm −3 to 10 15 cm −3 were studied by infrared light scattering tomography, scanning infrared microscopy, transmission electron microscopy and electron beam induced current. It was established that an increasing N content improves the uniformity of the radial distribution of precipitates in the bulk of the wafer, the density of precipitates reaching a level of ∼ 10 9 cm −3. The width of the denuded zone varies in the range from 15 µm to 70 µm depending on radial position and N doping level. Electron microscopy revealed lower oxide precipitate densities of about 10 5 to 10 8 cm −3. The results are interpreted in terms of existence of agglomerates of nanometer size precipitate nuclei and/or by the defect-induced strain relaxation around the precipitates.

A contribution to oxide precipitate nucleation in nitrogen doped silicon

“…Complexes of nitrogen, oxygen, and intrinsic point defects are assumed to strongly influence the precipitation of interstitial oxygen in nitrogen-doped silicon [1][2][3][4][5][6][7]. Two reactions of complexes were theoretically determined by molecular mechanics calculations to be possible paths for oxygen precipitation in Ndoped silicon.…”

Pressure‐induced transformations of nitrogen implanted into silicon

“…Doping of CZ-silicon with nitrogen (N) is used for stimulation of oxygen (O) precipitation in CZ-Si for the internal gettering process [1]. The vacancy-type nitrogen complexes are considered as the probable nucleation centers for oxygen precipitation [2].…”

Modeling and experimental verification of the 300mm Ar anneal process

“…Furthermore, the upcoming low thermal budget processes in ULSI technologies need a so-called "ready-IG" wafer because common oxygen precipitation during the chip manufacturing process chain is not any more possible. Argon annealed wafers of 300 mm size are an ideal solution for this challenge [3][4][5][6][7] and deliver a "ready-IG" capability especially if nitrogen doping is used [8][9][10][11][12][13]. To ensure also a cost productive process one has to generate a deep understanding of preventing slip occurrence while keeping high ramp rates in the vertical batch anneal furnace.…”