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Table 3298. Comparison between FIB, electron beam and laser beam techniques.
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Focused ion beam (FIB) |
Electron beam (EB) |
Laser beam (LB) |
Lithography |
Capability of lithography |
Yes |
Yes |
Yes |
Write pattern in a resist |
Yes |
Yes |
Yes |
|
More |
Less |
|
Exposure depth in resist |
Very limited (e.g. <100 nm at 100 keV) |
Less limited |
Much less limited |
Impurity of source elements within resist
|
Is an issue |
Is not an issue |
Is not an issue |
Photoresist layer |
No need |
No need |
Need |
|
Negligible |
Not negligible |
|
Others |
|
= beam spot size |
>> beam spot size |
|
Generation of SE by per 1 particles at 20 kV
|
~1 - 2 |
~0.5 - 0.8 |
|
Generation of BSE by per 1 particles at 20 kV
|
0 |
~0.3 - 0.5 |
|
Generation of SI by per 1 particles at 20 kV
|
~0.3 |
0 |
|
Generation of X-ray by per 1 particles at 20 kV
|
0 |
~0.006 - 0.008 |
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Typical
energy |
≥100 keV for lithography, ≤50 keV sputtering, ≤30 keV for deposition |
5~20 keV for lithography and deposition |
- |
Focus ability |
More difficult, e.g. due to more chromatic aberration, etc. |
Easier, e.g. due to less chromatic aberration, etc. |
Easier, e.g. due to less chromatic aberration, etc. |
Depth of focus |
~20 μm |
~8-10 μm |
<2 μm for He-Cd laser |
Typical surface
roughness (rms) |
≤2 nm |
1.5 nm |
25-100 nm |
Profile
accuracy |
<0.1 μm for lithography and sputtering, <0.5 μm for deposition |
<0.1 μm |
<0.1 μm for He-Cd laser |
|
~7 nm (better for small current) |
2~5 nm |
>1 μm for He-Cd laser |
Specimen limitation |
Gases cannot be analyzed and liquids are limited to those that have very limited volatility and will not contaminate the column and specimen chamber because specimens must be exposed to vacuum conditions. |
Any specimens |
* SEs: Secondary electrons
SIs: secondary ions
BSEs: Backscattering electrons
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