Specific Process Knowledge/Etch/ASE (Advanced Silicon Etch): Difference between revisions

Revision as of 18:24, 25 November 2007

The ICP-DRIE (Inductively Coupled Plasma - Deep Reactive Ion Etcher) tool at Danchip is manufactured by STS and is called the ASE (Advanced Silicon Etcher). The main purpose of the ASE is etching of silicon using Bosch process.

The Bosch process:

The Bosch process uses alternation between an etch cycle and a passivation cycle. In the case of the silicon etching on the ASE, an etch phase with SF₆ and O₂ alternates with a passivation phase with C₄F₈.

Two recipes have been optimized for the ASE. The specification is on a 10 % etch load wafer with trenches.

Shallolr: The shallow etch process will etch a 2 $\mu$ m feature down to 20 $\mu$ m trench.
Deepetch: The deep etch process will etch a 50 $\mu$ m feature down to 300 $\mu$ m trench.

The shallolr recipe
Common parameters		Multiplexed parameters
Parameter	Setting	Parameter	Etch	Passivation
Temperature	10^oC	SF₆ Flow	260 sccm	0 sccm
No. of cycles	31	O₂ Flow	26 sccm	0 sccm
Process time	5:56 mins	C₄F₄ Flow	0 sccm	120 sccm
APC mode	manual	RF coil	2800 W	1000 W
APC setting	86.8 %	RF Platen	16 W	0 W
		Cycle time	6.5 s	5 s

The deepetch recipe
Common parameters		Multiplexed parameters
Parameter	Setting	Parameter	Etch	Passivation
Temperature	20^oC	SF₆ Flow	230 sccm	0 sccm
No. of cycles	250	O₂ Flow	23 sccm	0 sccm
Process time	54:10 mins	C₄F₄ Flow	0 sccm	120 sccm
APC mode	manual	RF coil	2800 W	1000 W
APC setting	87.7 %	RF Platen	19 W	0 W
		Cycle time	8 s	5 s

@@ Line 5: / Line 5: @@
 The Bosch process uses alternation between an etch cycle and a passivation cycle. In the case of the silicon etching on the ASE, an etch phase with SF<sub>6</sub> and O<sub>2</sub> alternates with a passivation phase with C<sub>4</sub>F<sub>8</sub>.
-Two recipes have been optimized for the ASE:
+Two recipes have been optimized for the ASE. The specification is on a 10 % etch load wafer with trenches.
-* '''Shallolr'''
+* '''Shallolr''': The shallow etch process will etch a 2 <math>\mu</math>m feature down to 20 <math>\mu</math>m trench.
-This shallow etch process will produce a 20 <math>\mu</math>m
+* '''Deepetch''': The deep etch process will etch a 50 <math>\mu</math>m feature down to 300 <math>\mu</math>m trench.
-and a deep etch deepetch. They have been designed
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