Multi-mode narrow-band oscillation excimer laser
    7.
    发明授权
    Multi-mode narrow-band oscillation excimer laser 失效
    多模窄带振荡准分子激光器

    公开(公告)号:US4829536A

    公开(公告)日:1989-05-09

    申请号:US144000

    申请日:1987-11-30

    IPC分类号: G03F7/20 H01S3/106 H01S3/225

    摘要: Specification of an etalon included in a multimode, narrow-band oscillation excimer laster used as a light source for light exposure in photolithography are set to satisfy a relation S.lambda.W.lambda.R.lambda. (u,v)d.lambda..gtoreq..alpha., where .alpha. is an optical transfer function necessary for light exposure of resist according to a reticle pattern, R.lambda.(u,v) is an optical transfer function of monochromatic light for an illuminating system and a reduced-projection lens, W.lambda. is a weight which is applied to a waveform of a power spectrum in an oscillation laser beam at a wavelength .lambda.. Further, an inclination angle .lambda. of the etalon in its normal direction with respect to an optical axis when the etalon is provided between the chamber and rear mirror is set to satisfy a relation .theta.>tan.sup.-1 S/2A, where S is a dimension of a beam at a beam output mirror and A is a distance between the etalon and beam output mirror, and an oscillation linewidth K is set to satisfy relations K=1/.lambda..sub.o [1/{cos (.theta.+.theta.')}-1/cos .theta.} and also K.ltoreq.x, where .lambda..sub.o is a selected wavelength when the beam is directed onto the etalon at a normal angle, .theta.' is a beam divergence angle, and x is an allowable linewidth of a light exposure system using the excimer laser as a light source.