The Low-Temperature Metal-Organic Chemical Vapor Deposition (Ltmocvd) Route to Amorphous Silicon Semiconductors

ABSTRACTPreliminary results are presented for a new approach proposed by the present investigators to solve the problem of light-induced degradation in amorphous silicon semiconductors. The approach uses low-temperature metal-organic chemical vapor deposition (LTMOCVD) of tailored organometallic precursors. The precursors employed are non-toxic, non-hazardous and easy to handle. In the present paper, a-Si:H films were grown, using argon with various hydrogen concentrations as carrier gas, in a cold-wall CVD reactor at a reactor pressure of 1-10 torr and substrate temperature in the range 300–450°C. Characterization studies were performed using x-ray diffraction (XRD), x-ray photoelectron spectroscopy (XPS), and extended electron-energy-loss fine structure spectroscopy (EXELFS). The results of these studies showed that the films were uniform, continuous, adherent and highly pure--contaminant levels were below the detection limits of XPS. In addition, EXELFS results showed that short-range order (SRO), consisting of the same tetrahedral coordinated units found in crystalline silicon, does exist in all the amorphous samples, regardless of hydrogen concentration. However, the degree of stuctural disorder in the silicon local tetrahedral units decreased as hydrogen was added.

Download Full-text

Low Temperature Metal Organic Chemical Vapor Deposition (LTMOCVD) of Electronic Materials

MRS Proceedings ◽

10.1557/proc-162-409 ◽

1989 ◽

Vol 162 ◽

Cited By ~ 1

Author(s):

Alain E. Kaloyeros ◽

Paul J. Toscano ◽

Richard B. Rizk ◽

Victor Tulchinsky ◽

Alex Greene

Keyword(s):

Chemical Vapor Deposition ◽

Low Temperature ◽

Vapor Deposition ◽

Crystalline Silicon ◽

Chemical Vapor ◽

Organic Chemical ◽

Semiconductor Surface ◽

Metal Organic ◽

Organic Chemical Vapor Deposition ◽

Deposition Techniques

ABSTRACTHigh quality amorphous and crystalline silicon carbide thin films were produced by low temperature metal-organic chemical vapor deposition (LTMOCVD) using the organometallic precursor tetraethynylsilane, Si(C2 H)4. LTMOCVD, which was developed by the present investigators, uses single source precursors containing all the elemental constituents desired in the target material already directly bonded. This approach eliminates the inherent limitations of conventional MOCVD where separate precursors are used for each of the individual components of the desired compound. LTMOCVD thus combines the ability to deposit films at low temperatures, which is characteristic of physical deposition techniques, with the ability to provide complete coverage at steps or irregularities on the semiconductor surface, which is characteristic of chemical deposition techniques. In addition, the precursors employed are non-toxic, non-hazardous and easy to handle. Consequently, LTMOCVD can produce compound semiconductors on thermally fragile or chemically sensitive substrates. The SiC films were grown in a hot-wall CVD reactor at a reactor pressure of 10−6-10−3 torr and substrate temperature in the range 300–700°C. Characterization studies were performed using electron diffraction (ED), Auger electron spectroscopy (AES), Rutherford backscattering (RBS), x-ray photoelectron spectroscopy (XPS), and electron energy loss spectroscopy (EELS). The results of these studies showed that the films were uniform, continuous, adherent and highly pure– contaminant levels were below the detection limits of the techniques employed.

Download Full-text