calculations of 3d weighting field profiles for 3d detectors

Calculations of 3D Weighting Field Profiles for 3D Detectors

Zheng Li

G. Carini, M. Li

3rd Workshop on Advanced Silicon Radiation Detectors (3D and P-type Technologies, Barcelona, Spain, April 14-16, 2004

BNL 3D detector: 1 column design

n+ , the collecting electrode column, 1

p+ (implant),0

p+ , 0

Weighting Field (1/cm)

n+ (column),0

cut plane @ 1um cut plane @ 2um

cut plane @ 4um cut plane @ 10um

n+ n+

n+ n+

Weighting Field (1/cm) Weighting Field (1/cm)

Weighting Field (1/cm) Weighting Field (1/cm)

Weighting field highest near the surface

cut plane @ 20um

cut plane @ 50um

cut plane @ 30um

cut plane @ 70um

n+ n+

n+ n+

Weighting Field (1/cm) Weighting Field (1/cm)

Weighting Field (1/cm) Weighting Field (1/cm)

Weighting field highest near the collecting n+ column, lowest under p+ electrodes,and is at ½ strength in the middle (non-zero)

cut plane @ 150um cut plane @ 250um

cut plane @ 268um cut plane @ 271um

n+ n+

n+

Weighting Field (1/cm) Weighting Field (1/cm)

Weighting Field (1/cm) Weighting Field (1/cm)

Cutline

CutlineWeighting Field (1/cm)

Potential

cut plane @ 280um

cut plane @ 300um

cut plane @ 290um

Weighting Field (1/cm) Weighting Field (1/cm)

Weighting Field (1/cm) Some weighting field still exists near the unprocessed back side (non-zero)

BNL 3D detector: 2 columns design

n+ , the collecting electrode column, 1

n+ (column)

p+ (column)

p+

Weighing field (1/cm)

cut plane @ 0um cut plane @ 150um

cut plane @ 250um cut plane @ 268um

n+ n+

n+ n+

Weighting Field (1/cm) Weighting Field (1/cm)

Weighting Field (1/cm) Weighting Field (1/cm)

Weighting field highest near the collecting n+ column, lowest between p+ columnsAnd non-collecting n+ column, and is at about ½ strength in the middle (non-zero)

Cutline Weighting Field (1/cm)

cut plane @ 271um cut plane @ 275um

cut plane @ 278um cut plane @ 281um

Weighting Field (1/cm) Weighting Field (1/cm)

Weighting Field (1/cm) Weighting Field (1/cm)

cut plane @ 285um cut plane @ 290um

cut plane @ 300um

Weighting Field (1/cm) Weighting Field (1/cm)

Weighting Field (1/cm) Some weighting field still exists near the unprocessed back side (non-zero)

3D detector: BNM/ITC - IRST

n+ , the collecting electrode column

n+ (column)

p+ (column)

p+

cut plane @ 0um

cut plane @ 12um

cut plane @ 7um

cut plane @ 17um

Weighting Field (1/cm) Weighting Field (1/cm)

Weighting Field (1/cm)Weighting Field (1/cm)

Weighting field lowest near the surface of p+ columns

cut plane @ 18um

cut plane @ 24um

cut plane @ 20um

cut plane @ 28um

Weighting Field (1/cm) Weighting Field (1/cm)

Weighting Field (1/cm) Weighting Field (1/cm)

cut plane @ 30um cut plane @ 50um

cut plane @ 150um cut plane @ 250um

n+ n+

n+ n+

Weighting Field (1/cm) Weighting Field (1/cm)

Weighting Field (1/cm) Weighting Field (1/cm)

Weighting field highest near the collecting n+ column, lowest between p+ columnsAnd non-collecting n+ column, and is at about ½ strength in the middle (non-zero) (same)

Cutline

cut plane @ 269um cut plane @ 271um

cut plane @ 280umcut plane @ 273um

n+ n+

n+ n+

Weighting Field (1/cm) Weighting Field (1/cm)

Weighting Field (1/cm) Weighting Field (1/cm)

cut plane @ 285um

cut plane @ 300um

cut plane @ 290um

n+ n+

n+

Weighting Field (1/cm) Weighting Field (1/cm)

Weighting Field (1/cm) Weighting field at the surface of n+ columns is similar to that of the STC 3D detector

Summary Weighting field in 3D detectors is highly non-uniform

But it is distributed all throughout the detector (for pitch 50 µm) In the middle of the cell (between 4 columns), the weighting field is about half of the maximum

So the main limiting factor for CEE in 3D detectors may be electric fields