Method for measuring stress gradients of film in different directions

Abstract

The invention provides a method for measuring stress gradients of a film in different directions. The method comprises the following steps: acquiring a slope equivalent coefficient KX1 of the film ina first direction based on an S11 stress gradient and a slope equivalent coefficient KX2 based on an S22 stress gradient through simulation; obtaining a slope equivalent coefficient KY1 based on the S11 stress gradient and a slope equivalent coefficient KY2 based on the S22 stress gradient of the film in the second direction through simulation; obtaining the slope K1 of the film in the first direction and the slope K2 of the film in the second direction through an actual test; and calculating the stress gradients of the film in the first direction and the second direction according to the KX1,the KX2, the KY1, the KY2, the K1 and the K2. The method is higher in measurement accuracy and simpler.

Description

Technical field

[0001] The invention relates to the field of semiconductor devices, in particular to a method for measuring stress gradients in different directions of a thin film.

Background technique

[0002] In the field of MEMS, stress gradients generally exist in the device structure, causing structural deformation and affecting device performance.

[0003] At present, the commonly used method to measure the stress gradient is: set up a series of single-ended fixed cantilever beam structures with different lengths, then measure the warpage of the end of the beams with different lengths, and then bring it into the formula to calculate the stress gradient. This method usually assumes that the stress gradients of S11 (positive stress in the X-axis direction) or S22 (positive stress in the Y-axis direction) are consistent.

[0004] However, in actual situations, the stress magnitudes of S11 or S22 of the film are often inconsistent, so that the above calculation method...

Examples

Embodiment 1

[0047] Reference attached figure 1 As shown, the present embodiment discloses a method for measuring stress gradients in different directions of a thin film, comprising steps:

[0048] T1. Obtain the slope equivalent coefficient K of the film in the first direction based on the S11 stress gradient through simulation X1 , Slope equivalent coefficient K based on S22 stress gradient X2 ;

[0049] T2. Obtain the slope equivalent coefficient K of the film in the second direction based on the S11 stress gradient through simulation Y1 , Slope equivalent coefficient K based on S22 stress gradient Y2 ;

[0050] T3. Obtain the slope K in the first direction of the film through actual testing 1 and the slope K in the second direction 2 ;

[0051] T4, according to K X1 、K X2 、K Y1 、K Y2 , and K 1 、K 2 Calculate the stress gradient in the first direction and the second direction of the film.

[0052] It should be noted that, in this embodiment, the above steps T1, T2, and T3 ...

Technical field

[0001] The invention relates to the field of semiconductor devices, in particular to a method for measuring stress gradients in different directions of a thin film.

Background technique

[0002] In the field of MEMS, stress gradients generally exist in the device structure, causing structural deformation and affecting device performance.

[0003] At present, the commonly used method to measure the stress gradient is: set up a series of single-ended fixed cantilever beam structures with different lengths, then measure the warpage of the end of the beams with different lengths, and then bring it into the formula to calculate the stress gradient. This method usually assumes that the stress gradients of S11 (positive stress in the X-axis direction) or S22 (positive stress in the Y-axis direction) are consistent.

[0004] However, in actual situations, the stress magnitudes of S11 or S22 of the film are often inconsistent, so that the above calculation method...

Examples

Embodiment 1

[0047] Reference attached figure 1 As shown, the present embodiment discloses a method for measuring stress gradients in different directions of a thin film, comprising steps:

[0048] T1. Obtain the slope equivalent coefficient K of the film in the first direction based on the S11 stress gradient through simulation X1 , Slope equivalent coefficient K based on S22 stress gradient X2 ;

[0049] T2. Obtain the slope equivalent coefficient K of the film in the second direction based on the S11 stress gradient through simulation Y1 , Slope equivalent coefficient K based on S22 stress gradient Y2 ;

[0050] T3. Obtain the slope K in the first direction of the film through actual testing 1 and the slope K in the second direction 2 ;

[0051] T4, according to K X1 、K X2 、K Y1 、K Y2 , and K 1 、K 2 Calculate the stress gradient in the first direction and the second direction of the film.

[0052] It should be noted that, in this embodiment, the above steps T1, T2, and T3 ...

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