Jin Hyung Ahn

Microwave-induced low-temperature crystallization of amorphous Si thin films

Abstract Microwave heating was utilized for low-temperature crystallization of amorphous Si (a-Si) films. Microwave heating lowered the annealing temperature and reduced the annealing time. By microwave heating the hydrogen in the amorphous films was diffused out long before the nucleation of polycrystalline Si (poly-Si). The combination of NiCl 2 coating on a-Si and microwave heating greatly reduced crystallization temperature. The combination of metal-induced crystallization and microwave-induced crystallization might be a useful technique to develop high-quality poly-Si films at low temperature.

Crystallization of Amorphous Silicon Thin Films Using a Viscous Nickel Solution

This work was performed with financial support from Korea Science and Engineering Foundation with contract no. 981-1212-036-2. The Korea Advanced Institute of Science and Technology assisted in meeting the publication costs of this article.

Finding interstitial oxygen in an Si substrate during low-temperature plasma oxidation

An Si substrate (100) was oxidized at a low temperature in inductively coupled oxygen plasma. Interstitial oxygen was found in the Si substrate at the initial stage of oxidation by IR measurements. The penetration depth of the interstitial oxygen was about 4 nm. An x-ray rocking curve of Si substrates showed a lower peak intensity due to lattice distortion by the interstitial oxygen. The refractive index of thin oxides, below which interstitial oxygen existed in the Si substrate, was smaller than the refractive index of thick oxides, below which no interstitial oxygen existed. The interstitial oxygen was found by plasma oxidation using O2 gas and N2O gas. The inductively coupled plasma oxidation using N2O gas was performed by atomic oxygen, not by molecular oxygen, indicating that atomic oxygen in plasma is responsible for the incorporation of interstitial oxygen.

Microstructural evolution of polycrystalline Si films during Ni-silicide-mediated lateral crystallization

The Korea Advanced Institute of Science and Technology assisted in meeting the publication costs of this article.

Effect of CdS annealing in (CdCl/sub 2/+CdS) atmosphere on CdTe cells

To increase grain size, solution-grown CdS films were annealed at 560/spl deg/C in a (CdCl/sub 2/+CdS) atmosphere, instead of CdCl/sub 2/ only environment. CdS was used to prevent the evaporation of CdS from the films. After 5 min annealing, the grain size increased from 10 nm to 100 nm and the surface morphology was very smooth and densely packed. The optical transmittance was greatly improved near E/sub g/, compared to that of CdS films annealed at 400/spl deg/C for 30 min in H/sub 2/. The efficiency of the CdTe solar cell was improved by fabricating with the CdS layer annealed in a (CdCl/sub 2/+CdS) atmosphere. The increase of the efficiency was mainly due to the increase of fill factor, which might be due to the decrease of defects at CdTe bulk and the CdS/CdTe interface.