Method for quickly establishing lithography process condition by a pre-compensation value

Patent metadata

Field	Value
Publication number	US-10409170-B2
Application number	US-201715800043-A
Country	US
Kind code	B2
Filing date	Oct 31, 2017
Priority date	Apr 25, 2017
Publication date	Sep 10, 2019
Grant date	Sep 10, 2019

Abstract

The present invention discloses a method for quickly establishing lithography process condition by a pre-compensation value, comprising: firstly determining a reference process condition of masks of which parameters are same, and then determining an optimum process condition of the first mask; thereafter, calculating a ratio of the optimum process condition of the first mask deviating from the reference process condition, wherein if the ratio is equal to or larger than a set threshold, the first mask is inspected, and if the ratio is less than the set threshold, an optimum process condition of the second mask is determined according to the ratio and the reference process condition of the second mask; and by analogy, determining optimum process conditions of the rest masks. The method of the present invention can quickly establish a lithograph process condition, reduce the trial production time for determining the optimum defocus amount and exposure amount.

First claim

The invention claimed is:

1. A method for establishing lithography process condition by a pre-compensation value, wherein, comprising the following steps of:
S 01 : marking masks with same parameters as a first mask, a second mask . . . an Nth mask, which are respectively corresponding to a first lithographic layer, a second lithographic layer . . . an Nth lithographic layer during a lithograph; wherein, N is a positive integer;
S 02 : determining, in reference process conditions of the first mask, second mask . . . Nth mask, defocus amounts as F 1BSL +/−F 1BSLW μm, F 2BSL +/−F 2BSLW μm . . . F NBSL +/−F NBSLW μm, according to experimental values of parameters of the lithography process conditions which are stored in a technology platform; and exposure amounts as E 1BSL +/−E 1BSLW mJ·cm −2 , E 2BSL +/−E 2BSLW mJ·cm −2 . . . E NBSL +/−E NBSLW mJ·cm −2 , according to experimental values in a technology platform;
S 03 : making a focal distance-energy matrix for a first lithographic layer corresponding to the first mask and determining the defocus amount as F 1EXP μm and exposure amount as E 1EXP mJ·cm −2 in an optimum process condition;
S 04 : calculating a ratio M of the optimum process condition of the first mask deviating from the reference process condition, the ratio M comprises a defocus amount ratio M 1 and an exposure amount ratio M 2 , and judging whether the defocus amount ratio M 1 or the exposure amount ratio M 2 exceeds a set threshold, wherein if M 1 or M 2 is equal to or larger than the set threshold, the first mask is inspected, and the step S 03 is repeated after a correction is performed, and if both of M 1 and M 2 are less than the set threshold, a step S 05 is started; S 05 : according to the ratio and the reference process condition of the second mask, determining an optimum process condition of the second mask, F 2EXP =F 2BSL +F 2BSLW ×M 1 μm, E 2EXP =E 2BSL +E 2BSLW M 2 mJ·cm −2 ; S 06 : by analogy, according to the ratio M and the reference process condition of the Nth mask, determining an optimum process condition of the Nth mask, F NEXP =F NBSL +F NBSLW M 1 μm, E NEXP =E NBSL +E NBSLW ×M 2 mJ·cm −2 ; wherein
in the step S 03 , a small batch of trial production is performed on the first lithographic layer corresponding to the first mask, to determine the optimum process condition as F 1EXP μm, exposure amount E 1EXP mJ cm −2 , the small batch of trial production comprises performing lithographic processes for multiple times under different process conditions, and measuring patterns after each lithographic process, thereby determining the optimum process condition according to CD values of the different patterns.

2. The method for establishing lithography process condition by a pre-compensation value according to claim 1 , wherein the defocus amount ratio M 1 =(F 1EXP −F 1BSL )/F 1BSLW , and the value of M 1 is within a range of 10% to 60%.

3. The method for establishing lithography process condition by a pre-compensation value according to claim 1 , wherein the exposure amount ratio M 2 =(E 1EXP −E 1BSL )/E 1BSLW and the value of M 2 is within a range of 8% to 60%.

4. The method for quickly establishing lithography process condition by a pre-compensation value according to claim 1 , wherein the parameters of the masks are same in the following ways: the types of the masks are the same, the specifications are the same, and the substrates for fabricating the masks are the same batch; wherein the type of the mask is a bipolar mask, a phase-shifting mask, or an alternating phase shift mask; the specification includes a measurement pattern type, a maximum defect allowed in linewidth, a magnification of zoom in or zoom out, and a roughness.

5. The method for establishing lithography process condition by a pre-compensation value according to claim 4 , wherein the substrate for fabricating the mask is a substrate formed by depositing Cr or MoSi on a quartz substrate.

Assignees

• Shanghai Huali Microelect Corp

Inventors

• Chen Qiaoli
• Yang Zhengkai

Classifications

• G03F7/70641

  Focus · CPC title

• G03F7/70525

  Controlling normal operating mode, e.g. matching different apparatus, remote control or prediction of failure · CPC title

• G03F7/70625 Primary

  Dimensions, e.g. line width, critical dimension [CD], profile, sidewall angle or edge roughness · CPC title

• G03F1/50

  Mask blanks not covered by G03F1/20 - G03F1/34; Preparation thereof · CPC title

• G03F7/70558

  Dose control, i.e. achievement of a desired dose · CPC title