JP2011049401A5

JP2011049401A5 -

Info

Publication number: JP2011049401A5
Application number: JP2009197237A
Authority: JP
Filing date: 2009-08-27
Publication date: 2012-10-04
Anticipated expiration: 2029-08-27

Description

上記目的を達成するために、光源からの光を用いてマスクを照明する照明光学系と、前記マスクのパターンを基板に投影する投影光学系とを備える露光装置において、前記投影光学系の瞳面に形成される光強度分布及び偏光分布を含む有効光源分布をコンピュータによって決定する決定方法であって、前記投影光学系の瞳面を複数の領域に分割する分割ステップと、前記分割ステップで分割した複数の領域のうち少なくとも１つの領域を選択する選択ステップと、前記選択ステップで選択した少なくとも１つの領域からの光が第１の方向の直線偏光であると仮定したときに前記投影光学系の像面上の少なくとも１つの評価点に形成される像の電場振幅ベクトル（Ｅ_ｘ１，Ｅ_ｙ１，Ｅ_ｚ１）を算出すると共に、前記選択ステップで選択した少なくとも１つの領域からの光が前記第１の方向に直交する第２の方向の直線偏光であると仮定したときに前記投影光学系の像面上の少なくとも１つの評価点に形成される像の電場振幅ベクトル（Ｅ_ｘ２，Ｅ_ｙ２，Ｅ_ｚ２）を算出する第１の算出ステップと、前記第１の算出ステップで算出した電場振幅ベクトル（Ｅ_ｘ１，Ｅ_ｙ１，Ｅ_ｚ１）、及び、電場振幅ベクトル（Ｅ_ｘ２，Ｅ_ｙ２，Ｅ_ｚ２）を用いて、前記選択ステップで選択した少なくとも１つの領域の偏光方向を決定する第１の決定ステップと、を有することを特徴とする。 To achieve the above object, in an exposure apparatus comprising an illumination optical system that illuminates a mask using light from a light source and a projection optical system that projects a pattern of the mask onto a substrate, the pupil plane of the projection optical system A determination method for determining an effective light source distribution including a light intensity distribution and a polarization distribution formed by a computer by dividing the pupil plane of the projection optical system into a plurality of regions, and dividing by the dividing step A selection step of selecting at least one of a plurality of regions, and an image of the projection optical system assuming that light from the at least one region selected in the selection step is linearly polarized light in a first direction to calculate at least one electric field amplitude vector of the image formed on the evaluation points on the surface _{_{(E x1, E y1, E}} z1), were selected by the selecting step An image formed at at least one evaluation point on the image plane of the projection optical system assuming that light from at least one region is linearly polarized light in a second direction orthogonal to the first direction. A first calculation step of calculating an electric field amplitude vector (E _x2 , E _y2 , E _z2 ), an electric field amplitude vector (E _x1 , E _y1 , E _z1 ) calculated in the first calculation step, and an electric field And a first determination step of determining a polarization direction of at least one region selected in the selection step using amplitude vectors (E _x2 , E _y2 , E _z2 ).

Claims

In an exposure apparatus comprising an illumination optical system that illuminates a mask using light from a light source, and a projection optical system that projects a pattern of the mask onto a substrate, a light intensity distribution formed on a pupil plane of the projection optical system, and A determination method for determining an effective light source distribution including a polarization distribution by a computer,
A dividing step of dividing the pupil plane of the projection optical system into a plurality of regions;
A selection step of selecting at least one region among the plurality of regions divided in the dividing step;
The electric field amplitude of an image formed at at least one evaluation point on the image plane of the projection optical system when it is assumed that light from at least one region selected in the selection step is linearly polarized light in a first direction. A vector (E _x1 , E _y1 , E _z1 ) is calculated, and light from at least one region selected in the selection step is assumed to be linearly polarized light in a second direction orthogonal to the first direction. A first calculation step for calculating an electric field amplitude vector (E _x2 , E _y2 , E _z2 ) of an image that is sometimes formed at at least one evaluation point on the image plane of the projection optical system;
Using the electric field amplitude vector (E _x1 , E _y1 , E _z1 ) calculated in the first calculation step and the electric field amplitude vector (E _x2 , E _y2 , E _z2 ), at least 1 selected in the selection step The angle between the polarization direction of one region and the polarization direction and the first direction is Ψ,

A first determining step to determine according to:
A determination method characterized by comprising:

The electric field amplitude vector (E _x1 , E _y1 , E _z1 ) and the electric field amplitude vector (E _x2 , E _y2 , E _z2 ) calculated in the first calculation step and the polarization determined in the first determination step A second calculation step of calculating a light intensity value, an image inclination value, or a logarithmic image inclination value of an image formed at at least one evaluation point on the image plane of the projection optical system based on the direction;
A second determination step of determining the light intensity of at least one region selected in the selection step based on the light intensity value, the image inclination value or the logarithmic image inclination value calculated in the second calculation step;
The determination method according to claim 1, further comprising:

In the second determination step, a value obtained by multiplying the light intensity value calculated in the second calculation step by a power of a dispersion value of the light intensity value, and the image inclination value calculated in the second calculation step are used as the image. A value obtained by multiplying the slope value by the power of the variance value or a value obtained by multiplying the logarithmic image slope value calculated in the second calculation step by the power of the variance value of the logarithmic image slope value is selected in the selection step. The determination method according to claim 2, wherein the determination is performed as the light intensity of at least one region.

In the first calculation step, the electric field amplitude vector (E _x1 , E _y1 , E _z1 ) is used by using a pupil function representing the pupil plane of the projection optical system including a wavefront aberration on the pupil plane of the projection optical system. and determination method according to any one of claims 1 to 3, characterized in that to calculate the electric field amplitude vector _{_{_{(E x2, E y2, E}}} z2).

As the electric field amplitude vector (E _x1 , E _y1 , E _z1 ), a weighted average value of partial differential vectors obtained by _performing partial differentiation by coordinates on the electric field amplitude vector (E _x1 , E _y1 , E _z1 ),
As the electric field amplitude vector (E _x2 , E _y2 , E _z2 ), a weighted average value of a partial differential vector obtained by _performing partial differentiation by coordinates on the electric field amplitude vector (E _x2 , E _y2 , E _z2 ) is used. The determination method according to claim 1.

Illuminating the mask using the effective light source distribution determined by the determination method according to any one of claims 1 to 5,
Projecting a pattern of the mask onto a substrate;
An exposure method comprising:

Exposing the substrate using the exposure method according to claim 6;
Developing the exposed substrate;
A device manufacturing method characterized by comprising:

The program for making a computer perform the determination method of any one of Claims 1 thru | or 5.