Napa milih metode epitaksi fase cair?

Sifat unik SiC nggawe tantangan kanggo tuwuh kristal tunggal. Cara pertumbuhan konvensional sing digunakake ing industri semikonduktor, kayata metode tarik lurus lan metode crucible mudhun, ora bisa ditrapake amarga ora ana fase cair Si:C=1:1 ing tekanan atmosfer. Proses wutah mbutuhake tekanan luwih saka 105 atm lan suhu sing luwih dhuwur tinimbang 3200 ° C kanggo entuk rasio stoikiometri Si: C = 1: 1 ing solusi, miturut petungan teoretis.

Dibandhingake karo metode PVT, metode fase cair kanggo tuwuh SiC duwe kaluwihan ing ngisor iki:

1. low dislocation density. the problem of dislocations in SiC substrates has been the key to constrain the performance of SiC devices. Penetrating dislocations and microtubules in the substrate are transferred to the epitaxial growth, increasing the leakage current of the device and reducing the blocking voltage and breakdown electric field. On the one hand, the liquid-phase growth method can significantly reduce the growth temperature, reduce the dislocations caused by thermal stress during cooling down from the high-temperature state, and effectively inhibit the generation of dislocations during the growth process. On the other hand, the liquid-phase growth process can realize the conversion between different dislocations, the Threading Screw Dislocation (TSD) or Threading Edge Dislocation (TED) is transformed into stacking fault (SF) during the growth process, changing the propagation direction, and finally discharged into the layer fault. The propagation direction is changed and finally discharged to the outside of the crystal, realizing the decrease of dislocation density in the growing crystal. Thus, high-quality SiC crystals with no microtubules and low dislocation density can be obtained to improve the performance of SiC-based devices.

2. Iku gampang kanggo éling luwih gedhe-ukuran landasan. Cara PVT, amarga suhu transversal angel dikontrol, ing wektu sing padha, negara fase gas ing bagean salib angel mbentuk distribusi suhu sing stabil, diametere luwih gedhe, luwih suwe wektu cetakan, luwih angel. kanggo ngontrol, biaya uga konsumsi wektu gedhe. Cara fase cair ngidini ekspansi diameter sing relatif prasaja liwat teknik pelepasan bahu, sing mbantu entuk substrat sing luwih gedhe kanthi cepet.

3. P-jinis kristal bisa disiapake. Cairan-phase cara amarga meksa wutah dhuwur, suhu punika relatif kurang, lan ing kahanan Al ora gampang kanggo volatilize lan ilang, Cairan-phase cara nggunakake solusi flux karo Kajaba saka Al bisa luwih gampang kanggo njupuk dhuwur. konsentrasi pembawa kristal SiC tipe-P. Cara PVT dhuwur ing suhu, parameter P-jinis gampang kanggo volatilize.

Kajaba iku, metode fase cair uga ngadhepi sawetara masalah sing angel, kayata sublimasi fluks ing suhu sing dhuwur, kontrol konsentrasi impurity ing kristal sing akeh, pembungkus fluks, tatanan kristal ngambang, sisa ion logam ing co-solvent, lan rasio. saka C: Si kudu strictly kontrol ing 1: 1, lan kangelan liyane.