Evaporation source and vacuum evaporator using the same
An evaporation source having a nozzle structure that makes the distribution of film thickness uniform in the width direction of a substrate and a vacuum evaporator using the same are provided. A vapor produced by evaporation or sublimation by heating to evaporation material is discharged from a long nozzle opening like a band. A deposited substrate is transferred in a direction perpendicular to the longitudinal direction of the nozzle opening while facing the nozzle opening. A discharge flow rate of vapor per unit area in the longitudinal direction of the nozzle opening is made to be maximum in a portion at a nozzle width direction position corresponding to a substrate edge position rather than a central part of the nozzle opening and a plurality of partition plates providing directivity to the flow of vapor are arranged inside the nozzle opening.
1. An evaporation source comprising:
a vaporizing chamber in which an evaporation material is housed and a vapor of the evaporation material is produced by vaporization or sublimation of the evaporation material by heating and a cabinet part that communicates with the vaporizing chamber and discharges the vapor produced in the vaporizing chamber like a band through a long nozzle opening;
a control plate arranged in the cabinet part, said control plate having passage holes formed in such a way that a discharge flow rate Q (Kg/m 2 sec) of the vapor per unit area in a longitudinal direction of the nozzle opening becomes maximum in a portion at a predetermined position in a nozzle width direction rather than a central part of the long nozzle opening; and
a plurality of partition plates arranged between the control plate and the long nozzle opening in a vertical direction so that the plurality of partition plates partition the long nozzle opening into a plurality of smaller nozzle openings in the longitudinal direction such that the vapor passing through each of the passage holes provided in the control plate is straightened in the vertical direction inside each of the smaller nozzle openings; and
wherein the discharge flow rate Q (Kg/m 2 sec) of the vapor per unit area of the long nozzle opening has a flow rate distribution in which the discharge flow rate Q increases monotonously from the central part toward the end of the long nozzle opening and, after reaching a maximum value at the predetermined position in the nozzle width direction, decreases monotonously.
2. The evaporation source according to claim 1 ,
wherein an arrangement pitch of the plurality of partition plates in both edge parts of the long nozzle is set narrower, compared with that in the central part of the long nozzle opening formed along the longitudinal direction.
3. A vacuum evaporator comprising: an evaporation source as claimed in claim 1 or 2 and
a deposited substrate arranged inside a vacuum chamber,
wherein the deposited substrate is transferred in a direction perpendicular to the longitudinal direction of the long nozzle opening in the vacuum chamber while facing the long nozzle opening of the evaporation source, and
wherein the discharge flow rate Q (Kg/m 2 sec) of the vapor per unit area of the long nozzle opening becomes maximum in a portion corresponding to a substrate edge portion.
4. The vacuum evaporator according to claim 3 , wherein a ratio of flow rate of a discharge flow rate Q 1 (Kg/m 2 sec) of vapor per unit area of the nozzle opening at the position facing the edge in the width direction of the deposited substrate to a discharge flow rate Q 0 (Kg/m 2 sec) of vapor per unit area of the nozzle opening in the central part of the nozzle opening is β (=Q 1 /Q 0 ), a value α(=β/H) obtained by dividing the β by the distance H (m) between the upper face of the nozzle opening and the deposited substrate is set in a range of 10 ≦α≦30.