Some general process trends
This page is supposed to gather some general process trends and good advise for designing IBE recipes.
Etch rate
| Etch rate
|
Parameters
|
| increases with
|
Beam current
|
| increases with
|
Beam voltage
|
| increases with
|
Beam current * Beam voltage
|
| not significantly effected by
|
Stage angle
|
| not significantly effected by
|
Accelerator voltage
|
Etch profile
Rotation speed
The rotation is activated to get a good uniformity over the wafer. The minimum number of rotation to get a good uniformity is 100 rotation for the hole etch. the maximum rotation speed is 20rpm. That means that an etch shorter that 5min cannot obtain a very good uniformity.
| Etch profile (goal 90dg)
|
Parameters
|
| improves with
|
Low stage angle (optimum around 5-10 dg)
|
| is effected by
|
Beam current (low I(B)(400mA) better than high I(B)(600mA))
|
| is effected by
|
Accelerator voltage * Stage angle
|
| not significantly effected by
|
Beam voltage
|
| Etch Length [min]
|
5
|
6
|
7
|
8
|
9
|
10
|
15
|
20
|
25
|
34
|
50
|
100
|
| Minimum rotation speed [rpm]
|
20
|
17
|
15
|
13
|
12
|
10
|
7
|
5
|
4
|
3
|
2
|
1
|
