Techneglas Sources: BoronPlus and PhosPlus

Positives:

1. Simple, no complex equipment needed.
2. Startup is low cost.
3. No reactivation cycles like Boron Nitride.
4. Exhibit a minimum of water absorption
5. Can be removed from diffusion boats. This results in long quartz ware life.
6. Extended time between tube deglaze operations, thus reducing furnace down time.
7. Controlled dopant release reduces silicon damage
8. Any carrier gas can be used: nitrogen, argon, helium.
9. Oxygen insensitive. Deposition process can be optimized for best electrical results.
10. Uniform and clean deposition, regardless of wafer size.
11. Technical support by FAB experienced Techneglas employees.
12. Comparable costs to other solid sources, like boron nitride.
13. Long use life.
14. During use, dimensional size remains the same due to its structural ceramic matrix.
15. Safe and easy to use. No health issue with handling of the sources.
16. High wafer load capacity, whole tube can be used.

Negative:

1. Gases are less expensive, but this is offset by the cost savings of the other positives of Techneglas’s sources.

Dopant Gases

Diborane (B₂H₆), BBr₃ (boron tribromide), Pockle or Phosphorous
Oxytrichloride (POCl₃), Boron Trimethyl (B(CH₃)₃),
Boron Trichloride (BCL₃)₃), and Phosphine (PH₃)

Positive:

1. Pure depositions
2. Material costs are low.

Negatives:

1. Glazing of furnace tube increases equipment down time.
2. Non-uniform deposition, which increasing problems with larger wafer size.
3. Gases required are toxic and problematic for health issues.
4. Gases required are corrosive.
5. Support and maintenance costs are higher due to the health and equipment requirements needed for the toxic and corrosive gases required.
6. Typically wafer load size is small, for good dopant uniform.

Spin On Dopants

Positive:

1. Simple application, use of coating equipment

Negatives:

1. Can have high surface damage
2. Very sensitive to trace impurities
3. Startup cost involves specialized coat equipment.

Ion Implant

Phosphine (PH₃), Diborane (B₂H₆), Boron Trifluoride (BF₃)

Positive:

1. Uniform doping
2. Safe during implantation use.

Negatives:

1. Dangerous gases must be used for implantation, health and safety requirements.
2. Startup cost is very capital intensive.
3. High maintenance cost, part costs, and down time.
4. Implantation has silicon channeling which can negatively impact electrical performance and final yields.
5. Silicon damage results from the implantation and additional processing is needed for annealing this damage.

Planar BN

Boron Nitride Solid Sources

Positives:

1. Uniform doping
2. Safe
3. Simple to use.

Negatives:

1. Impurities are deposited
2. Sources are very hygroscopic (absorbs moisture quickly). This causes resistivity consistency issues.
3. High silicon damage occurs due to high deposition rate.
4. Users observe source warpage during use.
5. Sources thin during use. This causes deposition uniformity problems as they lean in the boat during use.