CUSP磁場對8英寸半導體級硅晶體生長的影響(全球半導體晶體生長建模著名商業(yè)軟件FEMAG)

1、全球半導體晶體生長建模著名商業(yè)軟件FEMAG -CUSP磁場對8英寸半導體級硅晶體生長的影響 Report Bruker ASC Feb, 9, 2012,FEMAGSoft 2012,FEMAGSoft 2012,OBJECTIVE,PROCESS CONDITION CZ furnace - 8 inch diameter crystal, 24 inch diameter crucible To predict the impact of a CUSP magnetic field operating at 140 A with the neutral-axis located on t

2、he melt free surface. SIMULATION PROCESS The growth process is modeled as Time dependent simulation taking in to account the transient effects taking place during the growth of the crystal PARAMETERS OBSERVED The concentration of the Oxygen in the melt and crystal. The concentration of the Phosphoro

3、us in the melt and crystal The concentration of the Carbon in the melt and crystal,FEMAGSoft 2012,CRYSTAL RADIAL OXYGEN MEASUREMENT POSITIONS,FEMAGSoft 2011,PREDICTION OF RADIAL OXYGEN CONCENTRATION,FEMAGSoft 2012,PREDICTION OF RADIAL OXYGEN CONCENTRATION,FEMAGSoft 2012,PREDICTION OF OXYGEN CONCENTR

4、ATION ALONG THE HEIGHT OF THE CRYSTAL,FEMAGSoft 2012,PREDICTION OF CARBON CONCENTRATION ALONG THE HEIGHT OF THE CRYSTAL,FEMAGSoft 2012,PREDICTION OF PHOSPHOROUS CONCENTRATION ALONG THE HEIGHT OF THE CRYSTAL,FEMAGSoft 2012,CUSP vs NOCUSP - OXYGEN CONCENTRATION - CRYSTAL,FEMAGSoft 2012,CUSP vs NOCUSP

5、- CARBON CONCENTRATION - CRYSTAL,FEMAGSoft 2012,CUSP vs NOCUSP - PHOSPHOROUS CONCENTRATION-CRYSTAL,FEMAGSoft 2011,CUSP vs NO CUSP - PHOSPHORUS RESISTIVITY - CRYSTAL,FEMAGSoft 2011,PREDICTION OF RADIAL PHOSPHORUS RESISTIVITY,FEMAGSoft 2012,NOCUSP VS CUSP TEMPERATURE IN THE MELT,Animation Temperature-

6、melt.avi,FEMAGSoft 2012,NOCUSP vs CUSP MELT TURBULENT VISCOSITY,Animation Turbulent viscosity-melt.avi,FEMAGSoft 2012,NOCUSP vs CUSP-VELOCITY - a lower temperature along the bottom of the crucible when a cusp field is applied, leading to a lower oxygen dissolution in this region; this lower temperat

7、ure appears as an additional consequence of the lower melt flow turbulence, the associated heat transfer reduction, and the resulting cooling down of the bottom of the melt,FEMAGSoft 2012,EFFECT OF A CUSP MAGNETIC FIELD ON OXYGEN CONCENTRATION (continued),This lower oxygen concentration is the resul

8、t of: - a different flow configuration: with a cusp field, the main flow cell (also called a Proudman cell) extends farther from the axis and closer to the melt/gas interface, thereby facilitating oxygen evaporation, while without cusp field the main flow cell remains located under the solid/liquid

9、interface The radial segregation is not very different with or without cusp field, showing a strong radial segregation close to the crystal wall in both cases, as a consequence of the strong oxygen evaporation prevailing near the tri-junction,FEMAGSoft 2012,EFFECT OF A CUSP MAGNETIC FIELD ON CARBON

10、CONCENTRATION,The following observations can be drawn: There is very little difference in carbon concentration with or without a magnetic field The carbon concentration is almost uniform in the melt, whether or not a cusp field is applied. This concentration increases steadily as a consequence of th

11、e segregation effect taking place along the solidification interface,FEMAGSoft 2012,EFFECT OF A CUSP MAGNETIC FIELD ON PHOSPHORUS CONCENTRATION,The following observations can be drawn: There is very little difference in phosphorus concentration with or without a magnetic field Our model considers ph

12、osphorus evaporation at the melt/gas interface. However, this effect is currently very small due to the applied evaporation parameters of phosphorus Therefore, such as for carbon, the phosphorus concentration is almost uniform in the melt, whether or not a cusp field is applied. Again this concentra

13、tion increases steadily as a consequence of the segregation effect taking place along the solidification interface,FEMAGSoft 2012,PERSPECTIVES,In order to better analyze the effect of a cusp magnetic field on species concentration, the following aspects should be investigated: Performing the analysi

14、s with a locally adapted and finer meshes, in order to better resolve the dissolution and segregation boundary layers, and to better capture the radial segregation at the crystal wall Performing simulations with a modified position of the cusp field: the neutral plane location should be optimized in

15、 order to get a more uniform oxygen distribution in the crystal (with a reduced axial segregation) Doing a parametric study of the carbon transfer process, more specifically oriented on the carbon transfer at the melt gas interface. In addition integrate the potential transformation of carbon into s

16、ilicon carbide particles. Further investigating the effect of the cusp field on carbon and phosphorus distributions by tuning the material properties of these species. Indeed, in other projects we have observed some sensitivity of the results to the material properties which are not always as precis

17、e as expected and provided by the material suppliers. Taking into account the anisotropy of the melt flow turbulence when a magnetic field is applied,FEMAGSoft 2012,PERSPECTIVES,What FEMAGSoft can do: All the required simulation work is possible. However this work has to be performed very carefully in order to guarantee that exact quantitative results are obtained All the required model improvements are available. However the associated material data have to be cross-checked and valida