CN-121978111-A - Method for monitoring internal stress of semiconductor device film

Abstract

The application provides a method for monitoring internal stress of a semiconductor device film, which comprises the steps of sequentially forming a barrier layer and a low dielectric constant material layer on the surface of a metal layer on a semiconductor structure, then etching the barrier layer and the low dielectric constant material layer on the surface of the metal layer to form dense holes distributed in an array, and finally monitoring whether the metal layer is extruded into the holes by using dark field detection equipment and a scanning electron microscope to judge whether the internal stress of the semiconductor device film is abnormal.

Inventors

• ZHANG FANGZHOU
• MI LIN
• MA QIANG

Assignees

• 华虹半导体制造(无锡)有限公司

Dates

Publication Date

20260505

Application Date

20260122

Claims (10)

1. 1. A method of monitoring stress in a semiconductor device film, comprising: Providing a semiconductor structure, wherein a metal layer is formed on the semiconductor structure; Sequentially forming a barrier layer and a low-dielectric-constant material layer, wherein the barrier layer covers the metal layer, and the low-dielectric-constant material layer covers the barrier layer; coating a photoresist layer on the low dielectric constant material layer; forming hole patterns arranged in an array on the photoresist layer through a photoetching process to obtain a patterned photoresist layer; etching the low dielectric constant material layer and the barrier layer by taking the patterned photoresist layer as a mask, and stopping on the surface of the metal layer so as to form holes which are arranged in an array in the low dielectric constant material layer and the barrier layer; Monitoring whether a metal layer at the bottom of the hole is extruded into the hole by using dark field detection equipment and a scanning electron microscope; And if the metal layer at the bottom of the hole is not extruded into the hole, determining that the film internal stress of the semiconductor device is normal.
2. 2. The method for monitoring the internal stress of a semiconductor device film according to claim 1, wherein the distance between two adjacent holes in the same row or column is 150nm to 200nm in the holes arranged in an array.
3. 3. The method for monitoring the internal stress of a semiconductor device film according to claim 1, wherein the internal diameter of each hole is 300nm to 400nm in the holes arranged in an array.
4. 4. The method of claim 1, wherein the step of monitoring whether the metal layer at the bottom of the hole is pressed into the hole by using a dark field detection device in combination with a scanning electron microscope comprises: Using dark field detection equipment to online identify whether suspected defect sites of the extrusion protrusions of the metal layers exist in the semiconductor devices on the batch production line; If the suspected defect sites extruded and raised by the metal layer exist, further observing all the suspected defect sites in the semiconductor device by using a scanning electron microscope; And if the microscopic morphology of the extrusion protrusion of the metal layer is not observed at the suspected defect site through the scanning electron microscope, judging that the metal layer at the bottom of the hole is not extruded into the hole.
5. 5. The method for monitoring stress in a semiconductor device film according to claim 1, the metal layer is characterized in that the metal layer is made of copper.
6. 6. The method of monitoring stress in a semiconductor device film according to claim 1, wherein a ratio of a thickness of the metal layer to a thickness of the barrier layer is 5:1.
7. 7. The method of claim 1, wherein the barrier layer is nitrogen doped silicon carbide.
8. 8. The method of monitoring stress in a semiconductor device film according to claim 1, wherein the thickness of the barrier layer is 30nm.
9. 9. The method of claim 1, wherein the low-k material layer is fluorine doped silicon dioxide, silicon oxynitride, silicon oxycarbide, or porous organic silicon low-k material.
10. 10. The method of claim 1, wherein the low-k material layer and the barrier layer are etched by a wet etching process using the patterned photoresist layer as a mask and stopping on the surface of the metal layer, so as to form holes in the low-k material layer and the barrier layer in an array arrangement.

Description

Method for monitoring internal stress of semiconductor device film Technical Field The application relates to the technical field of semiconductor manufacturing, in particular to a method for monitoring internal stress of a semiconductor device film. Background Under the condition of high internal stress of the semiconductor device/structure film, the phenomena of film separation, metal ion (such as copper ion) migration and the like can occur after the subsequent long-time use, and the yield is affected. In a semiconductor device/structure, the difference in thermal expansion coefficients between a metal layer (e.g., metallic copper) and a barrier layer (e.g., NDC (nitrogen doped silicon carbide) layer) on the surface of the metal layer is large, wherein the thermal expansion coefficient of metallic copper is 17ppm/°c and the thermal expansion coefficient of NDC layer is 3ppm/°c. In the subsequent process cooling process, the shrinkage of the metal copper is larger, the shrinkage of the NDC layer is smaller, so that larger compressive stress is formed in the semiconductor device film, and the yield of the semiconductor device can be reduced after long-time use. In advanced semiconductor manufacturing factories, PWG (PLASMA WAVE Generation of plasma wave) equipment is generally used to measure internal stress, carrier concentration, mobility, etc. of a semiconductor device/structural film, so that abnormal conditions of the internal stress of the semiconductor device film can be effectively and accurately monitored. However, since the PWG measuring apparatus is expensive, many manufacturing lines are not equipped due to cost pressure, and conventional manufacturing factories not equipped with the PWG measuring apparatus cannot efficiently and accurately monitor whether the internal stress of the semiconductor device film is abnormal. Disclosure of Invention The application provides a method for monitoring internal stress of a semiconductor device film, which can solve the problem that conventional production and manufacturing factories without PWG measuring equipment cannot effectively and accurately monitor abnormal conditions of the internal stress of the semiconductor device film. The embodiment of the application provides a method for monitoring internal stress of a semiconductor device film, which comprises the following steps: Providing a semiconductor structure, wherein a metal layer is formed on the semiconductor structure; Sequentially forming a barrier layer and a low-dielectric-constant material layer, wherein the barrier layer covers the metal layer, and the low-dielectric-constant material layer covers the barrier layer; coating a photoresist layer on the low dielectric constant material layer; forming hole patterns arranged in an array on the photoresist layer through a photoetching process to obtain a patterned photoresist layer; etching the low dielectric constant material layer and the barrier layer by taking the patterned photoresist layer as a mask, and stopping on the surface of the metal layer so as to form holes which are arranged in an array in the low dielectric constant material layer and the barrier layer; Monitoring whether a metal layer at the bottom of the hole is extruded into the hole by using dark field detection equipment and a scanning electron microscope; And if the metal layer at the bottom of the hole is not extruded into the hole, determining that the film internal stress of the semiconductor device is normal. Optionally, in the method for monitoring internal stress of a semiconductor device film, in the holes arranged in an array, a distance between two adjacent holes in the same row or the same column is 150 nm-200 nm. Optionally, in the method for monitoring internal stress of a semiconductor device film, in the holes arranged in an array, the internal diameter of each hole is 300 nm-400 nm. Optionally, in the method for monitoring the internal stress of the film of the semiconductor device, the step of monitoring whether the metal layer at the bottom of the hole is extruded into the hole by using a dark field detection device and a scanning electron microscope comprises: Using dark field detection equipment to online identify whether suspected defect sites of the extrusion protrusions of the metal layers exist in the semiconductor devices on the batch production line; If the suspected defect sites extruded and raised by the metal layer exist, further observing all the suspected defect sites in the semiconductor device by using a scanning electron microscope; And if the microscopic morphology of the extrusion protrusion of the metal layer is not observed at the suspected defect site through the scanning electron microscope, judging that the metal layer at the bottom of the hole is not extruded into the hole. Optionally, in the method for monitoring internal stress of a semiconductor device film, the metal layer is made of copper. Optionally, in the method for monitor