Eylem Seç
Lattice location of transition metals in silicon by means of emission channeling
Başlık:
Lattice location of transition metals in silicon by means of emission channeling
Yazar:
Silva, Daniel José da, author.
Yazar Ek Girişi:
Fiziksel Tanımlama:
1 electronic resource (233 pages)
Genel Not:
Source: Dissertation Abstracts International, Volume: 76-07C.
Özet:
The behavior of transition metals (TMs) in silicon is a subject that has been studied extensively during the last six decades. Their unintentional introduction during the Si production, crystal growth and device manufacturing have made them difficult contaminants to avoid. Once in silicon they easily form deep levels, either when in the isolated form or when forming precipitates. One important effect is the reduction of efficiency of silicon-based devices, being dramatic, in particular, in photovoltaic applications. One way to avoid such effects is by engineering the location of the TM: some TM complexes or lattice sites of the isolated form do not introduce any level in the silicon bandgap. Which point defects lead to such passivation is still under debate. Another way is to mitigate the reduction of efficiency by reducing the dangling bonds of TMs with hydrogen. The most important and commonly used procedures to diminish the unwanted effects of the introduced deep levels are, nevertheless, based on the so-called gettering techniques, where TMs are forced to move away from the active area of devices. Although the macroscopic effects of all the gettering techniques are well known, the related microscopic mechanisms are still poorly understood, namely the TM complexes involved in gettering into defective regions, into p-type layers and by phosphorus diffusion.
TMs can also be used as magnetic dopants in semiconductors. So far, only binary semiconductors have been intensively addressed, after the discovery of dilute ferromagnetism of (Ga,Mn)As. However, the maximum found Curie temperature was only 185 K, which is too low for practical applications. Other semiconductors have hence been recently suggested, such as silicon. One important feature is the lattice sites occupied by TMs, and related fractions. It is currently well established that the incorporation of TMs on substitutional sites leads to thermally stable point defects with none-zero magnetic moment. One way to obtain substitutional TMs is by ion implantation. Which fraction is incorporated on S sites is, however, still unknown.
All these issues can be explored by investigating the lattice sites of implanted 3d TMs. In particular, different complexes will correspond to different lattice sites. Here, we have investigated the lattice location and thermal stability of the implanted 3d TM probes 56Mn, 59Fe, 61Co and 65Ni in both lightly and heavily doped n- and p-type Si by means of emission channeling experiments. In all cases we identified ideal substitutional (S) sites, displaced bond-centered (near-BC) sites and displaced tetrahedral interstitial (near-T) sites.
Notlar:
School code: 5896
Konu Başlığı:
Tüzel Kişi Ek Girişi:
Mevcut:*
Yer Numarası | Demirbaş Numarası | Shelf Location | Lokasyon / Statüsü / İade Tarihi |
---|---|---|---|
XX(678867.1) | 678867-1001 | Proquest E-Tez Koleksiyonu | Arıyor... |
On Order
Liste seç
Bunu varsayılan liste yap.
Öğeler başarıyla eklendi
Öğeler eklenirken hata oldu. Lütfen tekrar deneyiniz.
:
Select An Item
Data usage warning: You will receive one text message for each title you selected.
Standard text messaging rates apply.