Specific Process Knowledge/Thermal Process/Oxidation
Feedback to this page: click here
Oxidation
At Danchip we have seven furnaces for oxidation: A1, A2, A3, C1, C3, D1 and nobel. Oxidation can take place either by a dry process or a wet process. The film quality of dry oxide is better than for wet oxide with regards to density and dielectric constant. If the film quality for the wet oxide is acceptable then the thickness and the time it takes to grow the oxide often decides if a dry or wet oxidation is chosen.
- Dry oxide is used from 5 nm - 200 nm. Can be grown in furnaces: A1, A2, A3, C1, C3.
- Wet oxide with O2 and H2 can be grown in furnace: A1, A3.
- Wet oxide with H2O in a bubbler can be grown in furnaces: C1, C3, D1, nobel.
The standard recipes, quality control limits and results for the Boron Drive-in and Phosphorus Drive-in furnaces can be found here:
- Standard recipes, QC limits and results for the Boron Drive-in + Predep furnace (A1)
- Standard recipes, QC limits and results for the Phosphorus Drive-in furnace (A3)
Comparison of the six oxidation furnaces
| ' | A1 Boron drive-in |
A3 Phosphorous drive-in |
C1 Anneal oxide |
A2 Gate oxide |
C3 Anneal bond |
D1 APOX |
Noble |
| General description | Drive-in of boron deposited in the boron pre-dep furnace(A2) or drive-in of ion implanted boron. Can also be used for dry and wet oxidation. | Drive-in of phosphorous deposited in the phosphorous pre-dep furnace(A2) or drive-in of ion implanted phosphorous. Can also be used for dry and wet oxidation. | Oxidation and annealing of wafers from the B-stack and PECVD1. At the moment also used for general oxidation of 6" wafers. | Oxidation of gate-oxide and other especially clean oxides. | Oxidation and annealing of wafers from NIL. | Oxidation of very thick oxides | Oxidation and annealing for all materials. |
|---|---|---|---|---|---|---|---|
| Dry oxidation | x | x | x | x(with special permission) | x | . | x (after request) |
| wet oxidation with torch (H2+O2) | x | x | . | . | . | . | . |
| Wet oxidation with bubbler (water steam + O2) | . | . | x | . | x | x | x after request |
| Process temperature [ oC ] | 800-1150 | 800-1150 | 800-1150 | 800-1150 | 800-1150 | 1075 | . |
| Cleanliness of dry oxide (rated 1-5, 1 is best) | 2 | 2 | 3 | 1 | 4 | . | >5 |
| Cleanliness of wet oxide (rated 1-5, 1 is best) | 1 | 1 | 2 | . | 4 | 3 | >5 |
| Batch size | max. 30 wafers of 4" or 2" | max. 30 4" wafers or 2" wafers | max. 30 wafers of 6",4" or 2" | max. 30 4" wafers or 2" wafers | max. 30 4" wafers or 2" wafers | max. 200 4" | max. 30 wafers |
| Which wafers are allowed to enter the furnace: | A1 Boron drive-in |
A3 Phosphorous drive-in |
C1 Anneal oxide |
A2 Gate oxide |
C3 Anneal bond |
D1 APOX |
Noble |
| RCA clean* Si wafers with no history of Metals on | x | x | x | x (with special permission) | x | . | x |
| From Predep furnace directly (e.g. incl. Predep HF*) | From A1 | From A4 | x | . | x | . | x |
| Wafers directly from PECVD2 | . | . | x | . | x | . | x |
| Wafers directly from NIL bonding | . | . | . | . | x | . | x |
| All materials must enter the furnace | . | . | . | . | . | . | x |
*These wafers must be placed in a "transport box from RCA to furnace" using the RCA carrier when doing RCA or the pre-dep carrier after pre-dep.
Comparison method 1 and method 2 for the process
| A1: Boron Drive-in | A2: Gate Oxide | A3: Phosphorous Drive-in | C1: Anneal Oxide | C3: Anneal Bond | D4: APOX | Noble furnace | |
| Generel description | Generel description - method 1 | Generel description - method 2 | Generel description - method 3 | Generel description - method 4 | Generel description - method 5 | Generel description - method 6 | Generel description - method 7 |
| Parameter 1 |
|
|
|||||
| Parameter 2 |
|
|
|||||
| Substrate size |
|
|
|||||
| Allowed materials |
|
|
Oxidation curves
Generic calculator for wet/dry oxide thickness calculation
The following links give an approximate oxide time/thickness based on a general formula.
The curves below are based on measurements in our specific furnaces and give more accurate results.
A1 Furnace <100>-Si Wet Oxidation
A3 Furnace <100>-Si Wet Oxidation
Dry Oxidation on <100> and <111> wafer
- Dry oxidation
Dry oxide on <100> wafer. The y-axis is in Å and the x-axis is in minutes.
Dry oxide on <111> wafer. The y-axis is in Å and the x-axis is in minutes.
