Boron wafers

Diborane(6), B2H. This spontaneously flammable gas is consumed primarily by the electronics industry as a dopant in the production of siHcon wafers for use in semiconductors. It is also used to produce amine boranes and the higher boron hydrides. Gallery Chemical Co., a division of Mine Safety AppHances Co., and Voltaix, Inc., are the main U.S. producers of this substance. Several hundred thousand pounds were manufactured worldwide in 1990. 

The next step is the hydrogen reduction of the trichlorosilane (Reaction 2 above). The end product is a poly crystalline silicon rod up to 200 mm in diameter and several meters in length. The resulting EGS material is extremely pure with less than 2 ppm of carbon and only a few ppb of boron and residual donors. The Czochralski pulling technique is used to prepare large single crystals of silicon, which are subsequently sliced into wafers for use in electronic devices.1 1... 

The patterned wafer might next be placed in a diffusion furnace, where a first doping step is performed to deposit phosphoras or boron into... 

This spurious contribution could be attributed to the presence of boron nuclei in the metallized wafer. Boron is present in nature with two stable isotopes (10B, nB), one having nuclear spin 3/2 and abundance of 80.3%, and the other nuclear spin 3 and abundance of 19.7%. The nuclei have non-zero electric quadrupole moments. 

In the literature [55], typical energies involved in the nuclear quadrupole moments -crystalline electric field gradient interactions range up to A E 2x 10-25 J. The measured AE seems to confirm the hypothesis that the excess specific heat of the metallized wafer is due to boron doping of the Ge lattice. 

DC Conduction. Cross-sectional and top views of the test structures for the dc conduction measurements are shown in Figure 1. Fabrication begins with p-type silicon wafers 3 inches in diameter, which are first doped with boron on the front... 

Typically, a source gas such as boron trifluoride [7637-07-2], BF3, is exposed to an ion source that causes the gas to ionize. An analyzer discriminates between all the ionic particles using a magnetic field that can select particles having the correct mass-to-charge ratio to pass through the analyzer to an acceleration tube. The ions are accelerated in the tube and collimated into a beam that is scanned over the substrate wafer. The three primary parameters of any implantation process are the type of dopant species, the accelerating energy used for implantation, and the dose of the source gas. The dose is the total number of ions that enter the wafer. Dose, ( ), can be calculated... 

The source of boron nitride in equation 6 may be the disks about the size of a silicon wafer that are placed next to the wafers in the diffusion furnace. 

Figure 5.1-10 IR absorption spectrum of a boron-phosphorous-silicate glass coated wafer for the determination of the boron and phosphorous content of the Si02 coating (sample thickness less than 1 pm, resolution 4 cm ).

Additional work on dielectrics includes deposition of silica, PABS (lead aluminum boron silicates), PLZT (lead lanthanum zirconium titanate) and BST (barium strontium titanate) on Si-Ti-Pt wafers (Figure 2). The wafer specimens were patterned with metal electrodes and electronic properties were characterized. 

Boron (B)-doped (100) plane p-type CZ-wafers (PW) with 10 Qan in resistivity and 150 mm in a diameter were chemomechanicaly polished in commercial use. A n-type (100) plane epitaxial wafer (EW) with 10 Qcm and 150 mm was also prepared as the reference sample. Both wafers were treated with 9 times SCI and SC2 cleaning. The respective cleaning was made for 6 minutes at 80°c using the SCI solution with the composition of NH40H H202 H20=1 1 8. 

PS samples were prepared by anodic etching of 10 Q-cm (111) boron doped p-Si wafers in a HF solution (48 wt.%) C2H50H (1 1) at the current density of 10 mA/cm for 5 min. The samples were aged in air for 3 days. The magnetic treatment of PS was carried out in a constant magnetic field of 0.17 T for 12 days in air. The duration of the reference sample exposition to air without... 

Because ion-beam treatment effect on the electrical properties of the wafers is independent of the treatment temperature and ion type, one of the mechanisms of this influence is the formation of point defects. This can lead to (i) the positive charge creation in the surface oxide layer [2] (ii) transfer of boron atoms into the electrically inactive interstitial positions by the ion-beam generated Sii atoms... 

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