CN115993375A - Laser processing system and processing method for PFA sample preparation - Google Patents

Abstract

The invention discloses a laser processing system and a laser processing method for preparing a PFA sample, which belong to the technical field of PFA sample preparation and comprise a control center, a loading module, an SEM/FIB module and a plurality of laser processing modules, wherein the output end of the control center is connected with the input end of the loading module, the input end of the SEM/FIB module and the input end of each laser processing module, and the output end of the SEM/FIB module is connected with the input end of the control center; the loading module at least comprises a sample conveying device, and the SEM/FIB module and the laser processing module are arranged near the sample conveying device. According to the invention, SEM and EDX are integrated, a modular design laser processing system is adopted, the surface components of a sample processing area are analyzed, the optimal processing conditions and sequences are calculated by using a control center, the loading module is controlled to sequentially send samples to different laser processing modules, the laser processing modules are controlled to carry out rough digging, fine digging and FIB sheet preparation processing on the samples, the problem of PFA sample preparation is solved, and the processing time is shortened.

Description

Laser processing system and processing method for PFA sample preparation

Technical Field

The invention relates to the technical field of PFA sample preparation, in particular to a laser processing system and a processing method for PFA sample preparation.

Background

Advanced 3D packages typically analyze the cause of failure by first revealing the location of the defect in a non-destructive manner, followed by destructive Physical Failure Analysis (PFA) techniques to determine and resolve the root cause of the failure. However, in preparing the samples required for destructive analysis, it may be necessary to perform different stages of processing including rough digging, fine digging, flake sampling, etc., for different packaging materials (encapsulant, ceramic, metal …) and wafer materials (Si, siO2, siC, gaN …).

In general, PFA is prepared by selecting a laser source and its energy driving frequency (picosecond/femtosecond) for different materials to achieve the best material removal effect, so as to achieve the effect of high-efficiency removal. In addition, after laser machining, it is also often necessary to sample the wafer defect with FIB on the nano-scale sheet for finer TEM observations. At present, the PFA sample preparation processes are all processed by technicians station by station according to preparation experience, so that the PFA sample preparation process is very time-consuming and has high failure rate.

The PFA processing equipment currently commercially available includes: (1) The FIB and the Laser are directly integrated in the same Chamber, so that the FIB and the Laser are expensive, low in applicability and processing efficiency, cannot select different Laser sources according to materials, are easy to cause pollution and are inconvenient to maintain. (2) The Stand-alone laser processing machine has low processing efficiency (continuous operation cannot be performed according to different processing stages) and low applicability (different materials are required to use different laser equipment).

In view of this, the present inventors have made intensive studies to address this need, and have made the present invention.

Disclosure of Invention

In order to overcome the problems of time consumption and high failure rate in the preparation process of PFA samples in the prior art, which are all processed by technicians station by station according to preparation experience, the invention provides a laser processing system integrating SEM and EDX and adopting modularized design, which can solve the problem of PFA sample preparation and shorten the processing time, and the technical scheme is as follows:

the laser processing system for preparing the PFA sample comprises a control center, a loading module, an SEM/FIB module and a plurality of laser processing modules, wherein the output end of the control center is connected with the input end of the loading module, the input end of the SEM/FIB module and the input end of each laser processing module, and the output end of the SEM/FIB module is connected with the input end of the control center; the loading module at least comprises a sample conveying device, and the SEM/FIB module and the laser processing module are arranged near the sample conveying device.

The SEM and EDX are integrated, a modular design laser processing system is adopted, the surface components of a sample processing area are analyzed, the optimal processing conditions and sequences are calculated by using a control center, the loading module is controlled to sequentially send samples to different laser processing modules, the laser processing modules are controlled to perform rough digging, fine digging and FIB sheet preparation processing on the samples, the problem of PFA sample preparation is solved, and the processing time is shortened.

Preferably, the control center comprises a display screen, an input device, an operation device, a database and a control device, wherein the input end of the display screen is connected with the output end of the control device, the output end of the SEM/FIB module is connected with the input end of the input device, the output end of the input device is connected with the input end of the operation device, the database is in bidirectional connection with the operation device, the output end of the operation device is connected with the input end of the control device, and the output end of the control device is connected with the loading module, the SEM/FIB module and the input end of the laser processing module. Here, the control center can schedule proper laser processing modules, process conditions and sequences according to the EDX analysis result of the processing area, and can control all modules to perform sample transmission and processing.

Preferably, the SEM/FIB module has SEM and FIB devices and at least comprises an EDX detection device which has EDX Mapping function and can analyze material components.

Preferably, the sample transfer apparatus is a manipulator, a conveyor belt or a turntable; when the sample conveying device is a mechanical arm, the sample is conveyed by the mechanical arm in the Load-lock module and can also move up and down.

After a worker places a sample, he can take, place and transfer the sample between the modules.

The SEM/FIB module and the laser processing modules are annularly arranged around the sample conveying device;

or the SEM/FIB module and the laser processing modules are vertically stacked and arranged at one side of the sample conveying device. The modules may be stacked vertically or arranged in a spread.

Preferably, each laser processing module at least comprises a group of laser sources, wherein the laser sources are selected from one of a UV light source, a Green light source and an IR light source, and the sample structural material can be removed and processed.

The arrangement of the laser processing modules can be built around the periphery of the loading module (shortest transmission path) or vertically stacked (small occupation area and high expandability).

Preferably, each laser processing module is a separate chamber, so that no mutual contamination occurs, the chamber can be in a vacuum or atmospheric environment, and at least one set of laser sources is provided. Different laser processing modules can be constructed according to the common requirements. Each module provides different laser sources, or pulse energy.

Here, a small cavity module is adopted, and the vacuum pumping is fast.

Preferably, an exhaust system is also included, which communicates with the interior of the separate chamber.

Preferably, the loading module is mutually communicated with the SEM/FIB module and the laser processing module, and airtight gates are arranged at the communicating positions of the loading module, the SEM/FIB module and the laser processing module.

Preferably, the scanning electron microscope is arranged on the laser processing module, so that SEM images can be observed.

Preferably, the system can also be added with other functional modules to properly modify or clean the sample, such as Plasma treatment, dry etching, static electricity or dust removal, etc.

The invention also provides a processing method of the laser processing system for preparing the PFA sample, which comprises the following steps:

step one, controlling a loading module to send a sample placed on the loading module into an SEM/FIB module;

controlling an SEM/FIB module to perform EDX analysis on the sample according to the set designated sample processing position and depth, analyzing the surface components of the sample processing area, receiving an analysis result, and formulating and calculating the optimal processing conditions and sequence according to the processing area and component data of the designated sample and referring to a database;

and thirdly, controlling the loading module to sequentially send the samples to different laser processing modules according to the optimal processing conditions and sequence, and controlling the laser processing modules to perform rough digging, fine digging and FIB sheet preparation processing on the samples.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings that are needed in the embodiments will be briefly described below, it being understood that the following drawings only illustrate some examples of the present invention and therefore should not be considered as limiting the scope, and other related drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a schematic diagram of a preferred laser processing system according to the present invention;

FIG. 2 is a schematic diagram of a control center control structure according to a preferred embodiment of the present invention.

Detailed Description

For the purpose of making the objects, technical solutions and advantages of the embodiments of the present invention more apparent, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is apparent that the described embodiments are some embodiments of the present invention, but not all embodiments. Thus, the following detailed description of the embodiments of the invention, as presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, based on the embodiments of the invention, which are apparent to those of ordinary skill in the art without inventive faculty, are intended to be within the scope of the invention.

As shown in fig. 1 and 2, the laser processing system for PFA sample preparation comprises a control center 1, a loading module 2, an SEM/FIB module 3 and a plurality of laser processing modules 4, wherein the output end of the control center 1 is connected with the input end of the loading module 2, the input end of the SEM/FIB module 3 and the input end of each laser processing module 4, and the output end of the SEM/FIB module 3 is connected with the input end of the control center 1; the loading module 2 comprises at least one sample transfer device 21, and the SEM/FIB module 3 and the laser processing module 4 are both arranged near the sample transfer device 21.

Here, the control center 1 includes a display screen 11, an input device 12, an operation device 13, a database 14 and a control device 15, where the input end of the display screen 11 is connected to the output end of the control device 15, the output end of the SEM/FIB module 3 is connected to the input end of the input device 12, the output end of the input device 12 is connected to the input end of the operation device 13, the database 14 is bidirectionally connected to the operation device 13, the output end of the operation device 13 is connected to the input end of the control device 15, and the output end of the control device 15 is connected to the input ends of the loading module 2, the SEM/FIB module 3 and the laser processing module 4. Here, the control center can schedule proper laser processing modules, process conditions and sequences according to the EDX analysis result of the processing area, and can control all modules to perform sample transmission and processing.

It is easy to understand that the SEM/FIB module 3 has SEM and FIB devices and at least comprises an EDX detection device having EDX Mapping function for analyzing the material composition.

In actual operation, according to the functional characteristics of the sample conveying device 21, the sample conveying device 21 may be a manipulator, a conveyor belt or a turntable; when the sample conveying device is a mechanical arm, the sample is conveyed by the mechanical arm in the Load-lock module and can also move up and down.

After a worker places a sample, he can take, place and transfer the sample between the modules.

The SEM/FIB module 3 and the laser processing modules 4 are annularly arranged around the sample conveying device 21;

or the SEM/FIB module 3 and the laser processing modules 4 are vertically stacked on one side of the sample conveying device 21, and the modules can be vertically stacked or distributed.

Each laser processing module 4 at least comprises a group of laser sources, wherein the laser sources are selected from one of a UV light source, a Green light source and an IR light source, so that the sample structural material can be removed and processed, and the laser sources of different laser processing modules can be used for removing and processing.

The arrangement of the laser processing modules can be built around the periphery of the loading module (shortest transmission path) or vertically stacked (small occupation area and high expandability).

Each laser processing module is an independent cavity, so that the laser processing modules cannot pollute each other, the cavity can be in vacuum or atmospheric environment, and at least one group of laser sources is arranged. Different laser processing modules can be constructed according to the common requirements. Each module provides different laser sources, or pulse energy.

Here, a small cavity module is adopted, and the vacuum pumping is fast.

As a preferred embodiment, an exhaust system 5 is also included, which communicates with the interior of the separate chamber.

The loading module 2 is communicated with the SEM/FIB module 3 and the laser processing module 4, and airtight gates are arranged at the communicating positions of the loading module 2, the SEM/FIB module 3 and the laser processing module 4.

The scanning electron microscope is arranged on the laser processing module 4, so that SEM images can be observed.

The system can also be added with other functional modules to properly modify or clean the sample, such as Plasma treatment, dry etching, static electricity or dust removal, etc.

The embodiment also provides a processing method of the laser processing system for preparing the PFA sample, which comprises the following steps:

step one, controlling a loading module to send a sample placed on the loading module into an SEM/FIB module;

controlling an SEM/FIB module to perform EDX analysis on the sample according to the set designated sample processing position and depth, analyzing the surface components of the sample processing area, receiving an analysis result, and formulating and calculating the optimal processing conditions and sequence according to the processing area and component data of the designated sample and referring to a database;

and thirdly, controlling the loading module to sequentially send the samples to different laser processing modules according to the optimal processing conditions and sequence, and controlling the laser processing modules to perform rough digging, fine digging and FIB sheet preparation processing on the samples.

The above description is only of the preferred embodiments of the present invention and is not intended to limit the present invention, and various modifications and variations may be made to the present invention by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims (10)

1. The laser processing system for preparing the PFA sample is characterized by comprising a control center, a loading module, an SEM/FIB module and a plurality of laser processing modules, wherein the output end of the control center is connected with the input end of the loading module, the input end of the SEM/FIB module and the input end of each laser processing module, and the output end of the SEM/FIB module is connected with the input end of the control center; the loading module at least comprises a sample conveying device, and the SEM/FIB module and the laser processing module are arranged near the sample conveying device.

2. The laser processing system for preparing a PFA sample according to claim 1, wherein the control center comprises a display screen, an input device, an operation device, a database and a control device, wherein the input end of the display screen is connected with the output end of the control device, the output end of the SEM/FIB module is connected with the input end of the input device, the output end of the input device is connected with the input end of the operation device, the database is connected with the operation device in a two-way manner, the output end of the operation device is connected with the input end of the control device, and the output end of the control device is connected with the input ends of the laser loading module, the SEM/FIB module and the processing module.

3. The system of claim 1, wherein the SEM/FIB module comprises an EDX detector.

4. The laser processing system for PFA sample preparation of claim 1, wherein said sample transfer means is a robot, a conveyor belt or a turntable;

the SEM/FIB module and the laser processing modules are annularly arranged around the sample conveying device;

or the SEM/FIB module and the laser processing modules are vertically stacked and arranged at one side of the sample conveying device.

5. The laser processing system for preparing a PFA sample of claim 1, wherein each laser processing module comprises at least one set of laser sources, wherein the laser sources are selected from one of UV light sources, green light sources, IR light sources.

6. The laser processing system for PFA sample preparation of claim 5, wherein each of said laser processing modules is a separate chamber and has at least one set of said laser sources.

7. The laser processing system for PFA sample preparation of claim 6, further comprising an exhaust system in communication with the interior of the separate chamber.

8. The laser processing system for preparing a PFA sample according to claim 1, wherein the loading module is mutually communicated with the SEM/FIB module and the laser processing module, and air-tight gates are arranged at the communicating positions of the loading module, the SEM/FIB module and the laser processing module.

9. The laser processing system for PFA sample preparation of claim 1, wherein said scanning electron microscope is provided on said laser processing module.

10. A processing method of the laser processing system for PFA sample preparation as claimed in any one of claims 1 to 9, comprising the steps of:

step one, controlling a loading module to send a sample placed on the loading module into an SEM/FIB module;

controlling an SEM/FIB module to perform EDX analysis on the sample according to the set designated sample processing position and depth, analyzing the surface components of the sample processing area, receiving an analysis result, and formulating and calculating the optimal processing conditions and sequence according to the processing area and component data of the designated sample and referring to a database;

and thirdly, controlling the loading module to sequentially send the samples to different laser processing modules according to the optimal processing conditions and sequence, and controlling the laser processing modules to perform rough digging, fine digging and FIB sheet preparation processing on the samples.

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