Scanning Electron Microscopy and X-Ray Microanalysis

185 12

of the cavity, the SEs generated deep in the cavity create addi-

tional generations of cascade multiplication, increasing the

signal compared to the flat surface of the specimen, making

the cavities appear bright relative to the flat surface.

References

Danilatos GD (1988) Foundations of environmental scanning electron

microscopy. Adv Electronics Electron Opt 71:109

Danilatos GD (1990) Mechanism of detection and imaging in the ESEM.

J Microsc 160:9

Danilatos GD (1991) Review and outline of environmental SEM at pres-

ent. J Microsc 162:391

Danilatos DD (1993) Introduction to the ESEM instrument. Microsc Res

Tech 25:354

Newbury D (1996) Imaging deep holes in structures with gaseous sec-

ondary electron detection in the environmental scanning electron

microscope. Scanning 18:474

150 mm1 0 mm

50 mm2 mm

. Fig. 12.14 Sequence of VPSEM images showing details revealed at the bottom of a cavity in polished Raney nickel alloy

+ 30 to

+ 600 V

1 - 20 torr

+V

+

+

+

+

. Fig. 12.15 Effect of extended gas path length created by a cavity

References