Electron-cyclotron resonance, ECR

The requirements of thin-film ferroelectrics are stoichiometry, phase formation, crystallization, and microstmctural development for the various device appHcations. As of this writing multimagnetron sputtering (MMS) (56), multiion beam-reactive sputter (MIBERS) deposition (57), uv-excimer laser ablation (58), and electron cyclotron resonance (ECR) plasma-assisted growth (59) are the latest ferroelectric thin-film growth processes to satisfy the requirements. 

Plasmas can be used in CVD reactors to activate and partially decompose the precursor species and perhaps form new chemical species. This allows deposition at a temperature lower than thermal CVD. The process is called plasma-enhanced CVD (PECVD) (12). The plasmas are generated by direct-current, radio-frequency (r-f), or electron-cyclotron-resonance (ECR) techniques. Eigure 15 shows a parallel-plate CVD reactor that uses r-f power to generate the plasma. This type of PECVD reactor is in common use in the semiconductor industry to deposit siUcon nitride, Si N and glass (PSG) encapsulating layers a few micrometers-thick at deposition rates of 5—100 nm /min. 

A microwave plasma can also be produced by electron cyclotron resonance (ECR), through the proper combination of electric and magnetic fields.Cyclotron resonance is achieved when the frequency of the alternating electric field is made to match the natural frequency of the electrons orbiting the lines of force of the... 

Figure 5.19. Schematic of electron cyclotron resonance (ECR) microwave deposition apparatns.

This reaction was also used to deposit epitaxial silicon at the temperature range of 1000-1040°C, but the deposit was generally unsatisfactory and the reaction is no longer used for that purpose. However, if the reaction is enhanced with a plasma using electron cyclotron resonance (ECR), fluxes may be independently controlled and high-quality epitaxial silicon deposits are obtained at temperatures below 500°C.P 1... 

Like synthetic diamond, C-BN is normally obtained by high-pressure processing. Efforts to synthesize it by CVD at low pressure are promising. It is deposited in an electron-cyclotron-resonance (ECR) plasma from a mixture of BF3 and either ammonia or nitrogen at 675°C on an experimental basis.F l Like CVD diamond, it is also deposited by the hot-filament method using diborane and ammonia diluted with hydrogen at 800°C.P 1... 

However, the nitrogen molecule has afar greater bonding energy than ammonia and is more difficult to dissociate into free atomic nitrogen active species. Consequently, the deposition rate is extremely slow. This can be offset by plasma activation with high frequency (13.56 MHz) or electron cyclotron resonance (ECR) plasmasP Ef l and with micro-wave activation. 

Some of the most significant developments in the CVD of Si02 include experiments in plasma CVD at 350°C via electron cyclotron resonance (ECR) to gain improved control of the deposition rate and obtain a quality equivalent to that of the thermally grown oxide (see Ch. 5). Deposition from diacetoxyditertiarybutoxy silane at 450°C has also been shown to significantly improve the Si02 film properties. " ]... 

Electron current density (je), 22 243 in silicon-based semiconductors, 22 238 Electron cyclotron resonance (ECR),... 

Electron cyclotron resonance (ECR) is used to deposit c-BN layers. Yokohama et al. [220] considered a negative substrate bias as an essential parameter for the deposition in ECR plasma to accelerate the ions formed in the plasma. A linear coherence was found between the bias and the etching rate of c-BN and h-BN, which was higher for h-BN. Three points are important for the crystal growth ... 

Combining an electron cyclotron resonance (ECR) plasma with a sputtering process is another option to seperate sputtering and plasma activation. It has been shown to be an attractive technique for the deposition of dielectric ZnO films [101]. 

AlGaN alloys doped with Si have been grown by electron cyclotron resonance (ECR) MBE at temperatures between 700 and 800°C [23,24], These layers were found to have net carrier concentrations of 1016 to 1019 cm 3 as measured by the Hall effect technique. The carrier concentration varies only slightly on alloying up to 25% Al. The samples were found to be smooth and free from cracks. Murakami et al also reported crack-free surfaces of Si doped Alo.1Gao.9N with a carrier concentration of up to 2 x 1018 cm 3 [25],... 

For GaN-based semiconductor lasers with a stripe geometry, it is necessary to fabricate a smooth and vertical facet for the resonator, which has been reported by Saotome et al [32,33] and Itaya et al [34], The RIBE system used in this study has an electron cyclotron resonance (ECR) ion source, and ECR plasma is generated by introducing a 2.45 GHz microwave into a horizontal discharge chamber on... 

At Argonne, a new positive ion injector for ATLAS based on an electron cyclotron resonance (ECR) plasma ion source is under construction (40). The... 

A second method of surface smoothing is to deposit a thick layer of SiOj and then a thin the layer by RIE or sputter etching. Because the sputter yield of the SiOj is greatest at an angle of 45°, the corners in the SiOj film etch quicker than the rest of the film and are therefore rounded by the etch process. With some deposition systems, for example, biased electron cyclotron resonance (ECR) plasma deposition, it is possible to deposit and etch concurrently, yielding a one-step process with a reduced deposition rate. ... 

---