TWI467645B - Chemical mechanical polishing method and system - Google Patents

Description

Chemical mechanical polishing method and system

This invention relates to a chemical mechanical polishing process and system, and more particularly to advanced process control for chemical mechanical polishing processes.

As the size of semiconductor components continues to shrink, the importance of global planarization of components in semiconductor processes is increasing. At present, the most common wafer surface planarization method is the Chemical Mechanical Polishing (CMP) process, which rotates the surface of the wafer on a polishing pad filled with polishing liquid to rotate the surface of the entire wafer. flattened.

When a semiconductor component is polished by a CMP process, the polishing time is too long to cause over Polishing. At this time, the resistance of each metal line on the device is too high to slow down the component speed, and the dielectric layer thereon is also It will be seriously damaged; when the grinding time is not long enough, the metal on the dielectric layer is not completely removed, which is called Under Polish phenomenon, which will also affect the performance of the component. Therefore, in the CMP process, the thickness of the control element is ground, and the above-mentioned excessive grinding or insufficient grinding phenomenon can be avoided to improve the yield of the product.

Please refer to the first figure, which is a conventional method for controlling the thickness of the polishing in the CMP process. The method uses feedback control to adjust the polishing time of the wafer. First, take 2~3 wafers for thickness measurement and grinding test (step 10), and use this test result to estimate the optimal grinding time of the first batch (Lot) wafer (step 11), with the estimated Optimum grinding time to grind the first batch of wafers (step 12), and after the first batch of wafers completes the CMP polishing process, re-sampling the thickness of the first batch of wafers after polishing (steps) 13), and the feedback result is fed back to the next batch of wafers to estimate the optimal grinding time of the next batch of wafers (step 14).

As described above, in the conventional CMP control method, the grinding parameters of the first batch of wafers are estimated only by sampling, thereby causing high yield loss; in addition, the feedback control system is used to estimate the subsequent batch crystals. The round grinding parameters are not only costly, but also provide an estimated grinding time for a batch of wafers and can not accurately control the grinding thickness of each wafer, thus failing to significantly reduce the grinding failure rate.

In order to solve the above problems of the prior art, the present invention proposes a chemical mechanical polishing method and system to improve the efficiency, accuracy and stability of the semiconductor component process.

The invention provides a chemical mechanical polishing method and system, which can accurately control the grinding thickness of components in the CMP process without using the feedback control flow of the prior art, thereby significantly reducing the yield loss and improving the product quality.

One aspect of the present invention provides a chemical mechanical polishing method comprising the steps of: providing a plurality of semiconductor elements; obtaining a size of one of each of the plurality of semiconductor elements; and grinding the each according to the size of each of the semiconductor elements A semiconductor component.

Another aspect of the present invention provides a method for a chemical mechanical polishing process, the method comprising the steps of: providing a plurality of articles, wherein each object has a physical parameter; obtaining the physical parameters of all of the plurality of objects; The physical parameter of each item determines the grinding parameters that are specific to each item.

A further aspect of the present invention provides a chemical mechanical polishing system for polishing a plurality of articles, and comprising a measuring device, a determining device and a grinding device; the measuring device is configured to obtain each of the plurality of objects a physical parameter of an object; the determining device is coupled to the measuring device for determining a grinding parameter specific to each object according to the physical parameter of each object; the grinding device is The decision device is coupled for grinding the article in accordance with the grinding parameters specific to each article.

The invention can be further understood by the following drawings and detailed description of specific embodiments:

The technical means of the present invention will be described in detail below. It is believed that the objects, features, and characteristics of the present invention will become more apparent and understood. Limit it.

Please refer to the second figure (A), which is an embodiment of the chemical mechanical polishing method of the present invention. The chemical mechanical polishing method includes the steps of: providing a plurality of semiconductor elements (step 20); using a measuring device in a measuring machine or other CMP process to obtain a size of each of the plurality of semiconductor elements ( Step 21); and, aligning each of the semiconductor elements in accordance with the size of each of the semiconductor elements obtained in step 21 (step 22).

According to the above concept, the plurality of semiconductor elements are, for example, a plurality of wafers, and may be other objects to be polished suitable for the CMP process.

For example, the measuring method of step 21 is: measuring the size of each semiconductor component one by one to obtain a size data of each semiconductor component, the size data may include a thickness of the semiconductor component, or the semiconductor The thickness of each material layer in the component, such as in angstroms ( ) is the unit.

Please refer to the second figure (B), which is an embodiment of step 22 in the second figure (A). Step 22 may include the steps of: defining a plurality of size intervals, each size interval corresponding to a specific polishing recipe (step 221); and a size interval to which the size of each semiconductor element belongs and the corresponding corresponding to each size interval A particular abrasive formulation is provided to provide a separate polishing recipe for each of the semiconductor components (step 222); and polishing each of the semiconductor components in accordance with the respective polishing recipe (step 223).

According to the above concept, the correspondence between the setting of the size interval and the specific polishing recipe is as shown in Table 1, and the content of the corresponding table can be designed or adjusted according to various types of objects to be polished or grinding machine parameters.

The X in Table 1 means that when the measured thickness of a component does not fall within a preset interval, the system does not produce an abrasive formulation for the component.

According to the above concept, the separate polishing recipe includes a grinding time for each semiconductor component, and may further include other grinding parameters such as temperature, pressure or abrasive material; the size interval may include at least 20 intervals; and the size An interval difference of the interval is, for example, about 100 angstroms ( ). It should be noted that the number of intervals included in the size interval and the interval difference between each interval can be designed according to the actual needs of the grinding process.

Please refer to the third figure, which is another embodiment of the chemical mechanical polishing method of the present invention. The chemical mechanical polishing method includes the steps of: providing a plurality of articles to be ground (step 31), wherein each of the plurality of objects has a physical parameter; obtaining the physical parameters of all of the plurality of objects (step 32); Determining the grinding parameters specific to each object according to the physical parameter of each object (step 33); wherein step 32 is, for example, measuring one size of each object one by one to obtain all of the plurality of objects And a physical parameter; wherein the physical parameter comprises at least a thickness of the object, and the grinding parameter comprises at least one grinding time.

According to the above concept, the object is a semiconductor component, such as a wafer.

Please refer to the fourth figure, which is an embodiment of the chemical mechanical polishing system of the present invention. The chemical mechanical polishing system 4 includes: a measuring device 41 for obtaining a physical parameter of each of the plurality of objects to be ground; a determining device 42 coupled to the measuring device 41 for Determining the grinding parameters specific to each object according to the physical parameter of each object; and a grinding device 43 coupled to the determining device 42 for determining the grinding parameters specific to each object Grinding each item. In the fourth figure, the direction of the arrow represents the direction of transport of the article in the chemical mechanical polishing system 4.

In accordance with the above concept, the decision device 42 is, for example, a polishing recipe generator that can be built in or input by an operator, such as a correspondence table 40 of Table 1, when the decision device 42 receives each of the measurements from the measurement device 41. After the physical parameter of the object, a specific grinding recipe can be generated for each object according to the physical parameter of the object and the correspondence table 40, and the specific grinding recipe includes the grinding parameters exclusive to each object.

According to the above concept, the object is a semiconductor component, such as a wafer; the physical parameter of each component includes at least a thickness of each object, and the polishing parameter includes at least one polishing time.

Please refer to Figure 5 (A) and Figure 5 (B). Figure 5 (A) shows the average thickness of each batch of 25 wafers before grinding. Figure 5 ( B) that, after grinding the 25 batches of wafers using the chemical mechanical polishing method and system of the present invention, the average thickness of each batch of wafers can be seen to enable the grinding to be completed using the polishing method and system of the present invention. The thickness of the semiconductor components is quite average.

In summary, the closed-loop control system of the prior art grinds each batch of objects according to the feedback signal. The present invention uses an open-loop automation system for each CMP process. An abrasive article produces an abrasive formulation that has the advantage of reducing system complexity while accurately controlling the thickness of the component. Therefore, the present invention is superior to various conventional technologies existing at present, and is uniquely an industrial value creation.

While the invention has been described above in terms of several preferred embodiments, it is not intended to limit the invention, and the invention may be modified and modified without departing from the spirit and scope of the invention. The scope of the invention is defined by the scope of the appended claims.

10. . . Take 2~3 wafers to measure thickness and grinding test steps

11. . . Steps to estimate the optimal grinding time for the first batch of wafers

12. . . Steps to grind the first batch of wafers

13. . . Steps to sample the thickness of the first batch of wafers

14. . . Steps to estimate the optimal grinding time for the next batch of wafers

20. . . Step of providing a plurality of semiconductor components

twenty one. . . Steps to obtain the dimensions of each semiconductor

twenty two. . . The step of grinding each of the semiconductor elements in accordance with the size of each of the semiconductor elements

221. . . Steps to define a complex size interval

222. . . The steps of providing separate grinding recipes according to the size interval to which each semiconductor component belongs

223. . . The step of grinding each semiconductor component according to the respective polishing recipe

31. . . Steps to provide multiple objects

32. . . Steps to get the physical parameters of all objects

33. . . The step of determining the grinding parameters specific to each object based on the physical parameters of each object

4. . . Chemical mechanical polishing system

40. . . Correspondence table

41. . . Measuring device

42. . . Decision device

43. . . Grinding device

First: Chemical mechanical polishing process of the prior art;

Figure 2 (A): an embodiment of the chemical mechanical polishing method of the present invention;

Second diagram (B): an embodiment of step 22 in the second diagram (A);

Third: another embodiment of the chemical mechanical polishing method of the present invention;

Figure 4: A schematic view of the chemical mechanical polishing system of this case;

Figure 5 (A): Schematic diagram of the average thickness of a plurality of wafers before grinding; and

Fifth Figure (B): Schematic diagram of the average thickness of a plurality of wafers after polishing using the chemical mechanical polishing method and system of the present invention.

20. . . Step of providing a plurality of semiconductor components

twenty one. . . Steps to obtain the dimensions of each semiconductor

twenty two. . . The step of grinding each of the semiconductor elements in accordance with the size of each of the semiconductor elements

Claims (20)

A chemical mechanical polishing method comprising: providing a plurality of semiconductor elements; obtaining a size of one of each of the plurality of semiconductor elements; and grinding each of the semiconductor elements in accordance with the size of each of the semiconductor elements. The method of claim 1, wherein the plurality of semiconductor elements are a plurality of wafers. The method of claim 1, wherein the step of obtaining the size of each of the semiconductor elements comprises measuring the size of each of the semiconductor elements one by one. The method of claim 1, wherein the size comprises a thickness of each of the semiconductor elements. The method of claim 1, wherein the step of grinding each of the semiconductor elements comprises: providing a separate polishing recipe for each of the semiconductor elements in accordance with the size of each of the semiconductor elements; and The formulation is ground to grind the each semiconductor component. The method of claim 5, wherein the separate abrasive formulation comprises a milling time. The method of claim 5, wherein the step of providing the separate abrasive formulation comprises the steps of: defining a plurality of size intervals, each size interval corresponding to a particular abrasive formulation; and according to each of the semiconductor components The size interval to which the size belongs and the particular polishing recipe corresponding to each size interval provide the respective polishing recipe for each of the semiconductor components. The method of claim 7, wherein the size interval comprises at least 20 intervals. The method of claim 7, wherein the interval of the size interval is 100 angstroms ( ). A method for a chemical mechanical polishing process, the method comprising: providing a plurality of articles, wherein each of the plurality of objects has a physical parameter; obtaining the physical parameters of all of the plurality of objects; and The physical parameters are used to determine the grinding parameters that are specific to each object. The method of claim 10, wherein the object is a semiconductor component. The method of claim 10, wherein the object is a wafer. The method of claim 10, further comprising the step of measuring one of the dimensions of each of the objects one by one to obtain the physical parameters of all of the plurality of objects. The method of claim 10, wherein the physical parameter comprises a thickness of the object. The method of claim 10, wherein the grinding parameter comprises a grinding time. A chemical mechanical polishing system comprising: a measuring device for obtaining a physical parameter of each of the plurality of objects; a determining device coupled to the measuring device for relying on each of the objects The physical parameters determine the grinding parameters specific to each item; and a grinding device coupled to the determining device for grinding the object according to the grinding parameters specific to each of the items. The system of claim 16, wherein the object is a semiconductor component. The system of claim 16, wherein the object is a wafer. The system of claim 16 wherein the physical parameter comprises a thickness of the article. The system of claim 16, wherein the grinding parameter comprises a grinding time.