High Contact Resistance from Preferential Oxidation of Silane Gas
High Contact Resistance from Preferential Oxidation of Silane Gas
Tuesday, October 29, 2024: 1:40 PM
204 (Hilton San Diego Bayfront)
Summary:
P+ and N+ contact chains suffered from high resistances. The impacted contact was partly filled with silicon dioxide (SiO2), which resulted from an accidental oxygen (O2) oxidation of the silane gas (SiH4) for the tungsten (W) seed deposition. The O2 in the air entered the deposition chamber through the leaky valve that controlled the flow of SiH4 for the W seed deposition. Subsequently SiH4 was oxidized by way of gas phase reaction to produce SiO2 particles that partly filled the contact. The leaky valve had been replaced. The problem had been solved. Research indicates the bond dissociation energy to produce SiO2 is lower than that to produce W of the same volume by the W seed deposition. In addition, the frequency of the molecular collision to produce SiO2 is also higher than that to produce W. Consequently the rate of the SiH4 oxidation is higher than that of the W seed deposition, which explains why the contact was predominantly filled with SiO2 particles instead of W.
P+ and N+ contact chains suffered from high resistances. The impacted contact was partly filled with silicon dioxide (SiO2), which resulted from an accidental oxygen (O2) oxidation of the silane gas (SiH4) for the tungsten (W) seed deposition. The O2 in the air entered the deposition chamber through the leaky valve that controlled the flow of SiH4 for the W seed deposition. Subsequently SiH4 was oxidized by way of gas phase reaction to produce SiO2 particles that partly filled the contact. The leaky valve had been replaced. The problem had been solved. Research indicates the bond dissociation energy to produce SiO2 is lower than that to produce W of the same volume by the W seed deposition. In addition, the frequency of the molecular collision to produce SiO2 is also higher than that to produce W. Consequently the rate of the SiH4 oxidation is higher than that of the W seed deposition, which explains why the contact was predominantly filled with SiO2 particles instead of W.