NOVELTY - Photoelectric conversion layer is deposited by plasma chemical vapor deposition at specific underlying layer temperature, specific chamber pressure, specific flow ratio of hydrogen gas to silane-type gas, and at least one of distance between the electrodes, chamber pressure, flow rate of silane-type gas and plasma discharging power are adjusted.    USE - The thin-film photoelectric conversion device is a silicon based solar cell.    ADVANTAGE - When a crystalline silicon-based photoelectric conversion layer is formed on an inexpensive substrate at a low temperature by CVD, film deposition rate is increased and film quality is improved. Thus the performance of the photoelectric conversion device is improved and its cost is reduced.    DETAILED DESCRIPTION - A method of fabricating a silicon-based thin-film photoelectric conversion device comprising at least one photoelectric conversion unit over a substrate (2), corresponding to a polycrystalline-type photoelectric conversion unit including a semiconductor layer of a first conductivity type, a crystalline silicon-based photoelectric conversion layer and a semiconductor layer of an opposite conductivity type selectively deposited by a chemical vapor deposition (CVD) method. When the photoelectric conversion layer is deposited by plasma CVD:    (i) the temperature of the underlying layer is less than 500 degreesC;    (ii) the pressure in the plasma reaction chamber (1) is more than 5 Torr;    (iii) the gas introduced in the reaction chamber contains silane-type gas and hydrogen gas as its main components, the flow rate of the hydrogen gas being more than 50 times larger than the flow rate of the silane-type gas; and    (iv) at least one of the following operations is performed:    (a) the distance between plasma discharge electrodes (3, 4) is increased so that it is at most 1 cm larger when the photoelectric conversion layer has been completely deposited than when the photoelectric conversion layer starts depositing, the distance being increased gradually or in steps after the photoelectric conversion layer has been deposited to 20 - 80% of its final thickness;    (b) a first pressure of more than 5 Torr is provided in the reaction chamber when the photoelectric conversion layer starts depositing, and the pressure is increased gradually or in steps to a second pressure until the photoelectric conversion layer is completely deposited;    (c) a silane-type gas flow rate is provided which has a flow rate 1.1 - 1.5 larger when the photoelectric conversion layer has been completely deposited than when the photoelectric conversion layer starts depositing, the flow rate of the silane-type gas being gradually increased for more than half the time required for depositing the photoelectric conversion layer; and    (d) a plasma discharging power of more than 100 mW/cm2 is provided, the plasma discharging power density being at most 15% smaller when the photoelectric conversion layer has been completely deposited than when the photoelectric conversion layer starts depositing, the plasma discharging power density being reduced gradually or in steps after the photoelectric conversion layer has been deposited to 20 - 80% of its final thickness.    DESCRIPTION OF DRAWING(S) - The diagram shows a schematic cross section of a single plasma CVD chamber including a movable plasma discharge electrode.    Chamber (1)    Substrate (2)    Electrodes (3, 4)