Method for converting special-shaped sheet and standard sheet tape-out

Abstract

The invention discloses a conversion method for a special-shaped chip and a standard chip tape-out, which relates to a semiconductor process technology and comprises the following steps: temporarily bonding a special-shaped chip on a first standard substrate slice through a bonding medium; performing dispensing filling on a gap between the temporarily bonded special-shaped chip and the first standard substrate slice; preparing a second standard substrate slice coated with a temporary bonding medium; carrying out secondary bonding on the first standard substrate slice after dispensing filling and the second standard substrate slice; performing de-bonding on the first standard substrate slice of the special-shaped chip after secondary bonding to form a temporary bonding standard slice; carrying out previous process tape-out on the temporary bonding standard sheet; and after the previous process is completed, carrying out de-bonding on the special-shaped chip, and taking down the second standard substrate slice to recover the special-shaped chip. The invention provides a method for converting a special-shaped chip into a standard chip for tape-out, so that the special-shaped chip can be compatible with existing standardized and automatic equipment, and automatic tape-out can be completely realized.

Description

Technical Field

[0001] The present application relates to the field of semiconductor process technology, and in particular to a method for converting special-shaped wafers into standard wafers. Background Art

[0002] Advanced HgCdTe focal plane photodetector technology expands single-band two-dimensional target imaging to three-dimensional imaging or simultaneously obtains the spectral characteristics of the target, and continues to develop in the direction of ultra-high resolution and high recognition capabilities. The material of the detector is required to be larger in size, higher in performance, and more complex in structure, so as to achieve the function of multiple responses to multiple target information. For HgCdTe epitaxial technology, as the material size increases, the liquid phase epitaxial material will be limited by the substrate size, and the composition and thickness will also have the problem of decreased uniformity. Among them, low thermal conductivity, large component segregation coefficient and low defect formation energy are the essential characteristics of CdZnTe materials, which are also the main factors that lead to the relatively slow progress of CdZnTe crystal growth technology and the difficulty in obtaining large-size, high-uniformity and low-defect density CdZnTe single crystal materials. At present, the size of HgCdTe epitaxial materials on the production line has reached 60mm x40mm, and the maximum size has reached 80mm x80mm.

[0003] When producing HgCdTe chips, due to their small size, various specifications, small total wafer volume and soft and brittle materials, there are no mature automated transmission and process equipment on the market. Therefore, in most processes such as chip transmission, photolithography, and wet processing, manual and semi-automatic transmission and wafer production methods are used (such as Figure 1 shown).

[0004] However, the traditional tape-out method of HgCdTe chips has many disadvantages:

[0005] The chip loss rate is extremely high: manual clamping, transfer and other steps will increase the chip fragmentation rate;

[0006] Difficulty in controlling process consistency: Too many people involved lead to great risks in ensuring process quality for both inter-wafer and intra-wafer consistency.

[0007] The cleanliness of chips is difficult to ensure: Since most processes are fully manual and semi-automatic, the demand for personnel on the production line remains high. The presence of personnel brings great difficulties to the cleanliness control of the clean room, so it is difficult to maintain the cleanliness of the chip surface. Summary of the invention

[0008] The embodiment of the present application provides a method for converting special-shaped wafers and standard wafers, which is used to solve the problems of high loss rate, large process fluctuations and low wafer efficiency encountered by small-sized chips during the wafer taping process.

[0009] The present application embodiment provides a method for converting a special-shaped wafer into a standard wafer, including:

[0010] Temporarily bonding the special-shaped chip to the first standard substrate through a bonding medium;

[0011] Filling the gap between the temporarily bonded special-shaped chip and the first standard substrate with glue;

[0012] preparing a second standard substrate sheet coated with a temporary bonding medium;

[0013] Performing secondary bonding on the first standard substrate sheet after being filled with glue and the second standard substrate sheet;

[0014] Debonding the first standard substrate sheet of the special-shaped chip after secondary bonding to form a temporary bonding standard sheet;

[0015] Performing front-end process tape-out on the temporary bonded standard wafer;

[0016] After the front-end process is completed, the special-shaped chip is debonded and the second standard substrate is removed to restore the special-shaped chip.

[0017] Optionally, the first standard substrate sheet meets grinding process conditions, and the second standard substrate sheet meets temperature resistance, chemical resistance and etching resistance requirements.

[0018] Optionally, after the gap between the temporarily bonded special-shaped chip and the first standard substrate is filled with glue, the following steps may also be performed:

[0019] The back side of the special-shaped chip is flattened to obtain a chip with parameters that meet the requirements.

[0020] Optionally, the special-shaped chip is temporarily bonded to the first standard substrate through a bonding medium, wherein the bonding medium is a pyrolytic bonding film and the bonding pressure is bonding at normal temperature and pressure;

[0021] The first standard substrate of the special-shaped chip after secondary bonding is debonded, wherein the debonding meets a set temperature rate.

[0022] Optionally, performing secondary bonding on the first standard substrate sheet after the dispensing filling and the second standard substrate sheet includes:

[0023] The bonding medium is a hot-press bonding adhesive, and the bonding medium meets the temperature resistance requirement of >180℃ / 30min; and,

[0024] Use one or more of acetone, ethanol, NMP, IPA, and developer chemical reagents, and meet the etching process requirements of ion implantation and etching;

[0025] Bonding process conditions: pressure: 20-40kN, bonding temperature 150-220℃ / 5-10min.

[0026] Optionally, after the front-end process is completed, the debonding process for debonding the special-shaped chip is laser debonding of a specified wavelength.

[0027] The embodiment of the present application provides a method for converting special-shaped chips into standard chips for tape-out, which can make the special-shaped chips compatible with existing standardized and automated equipment, and can fully realize automated tape-out, thus solving the problems of high loss rate, large process fluctuation and low tape-out efficiency encountered by small-size chips during the tape-out process.

[0028] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present application. Also, the same reference symbols are used throughout the accompanying drawings to represent the same components. In the accompanying drawings:

[0030] Figure 1 The basic process diagram of the conversion method of the special-shaped wafer and the standard wafer in the embodiment of the present application is shown;

[0031] Figure 2 The flowchart of the conversion method of the special-shaped wafer and the standard wafer in the embodiment of the present application is shown;

[0032] Figure 3 The figure is a schematic diagram of the process effect of the method for converting special-shaped wafers and standard wafers according to the embodiment of the present application. DETAILED DESCRIPTION

[0033] The exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0034] The present application embodiment provides a method for converting special-shaped wafers and standard wafers into wafers. Figure 1 As shown, the following steps are included:

[0035] In step S101, the special-shaped chip is temporarily bonded to the first standard substrate through a bonding medium;

[0036] In step S102, the gap between the temporarily bonded special-shaped chip and the first standard substrate is filled with glue; in a specific example, after the gap between the temporarily bonded special-shaped chip and the first standard substrate is filled with glue, the back of the special-shaped chip is flattened to obtain a chip with parameters that meet the requirements. For example, the flattening process is performed to obtain a chip with TTV, chip surface shape, etc. that meet the requirements.

[0037] In step S103, a second standard substrate sheet coated with a temporary bonding medium is prepared.

[0038] In step S104, the first standard substrate sheet filled with glue is bonded to the second standard substrate sheet for a second time.

[0039] In step S105, the first standard substrate sheet of the special-shaped chip after secondary bonding is debonded to form a temporary bonding standard sheet.

[0040] In step S106, the temporary bonded standard wafer is subjected to front-end process tape-out, wherein the front-end process includes processes such as photolithography, etching, and wet cleaning.

[0041] In step S107, after the front-end process is completed, the special-shaped chip is debonded and the second standard substrate is removed to restore the special-shaped chip.

[0042] The embodiment of the present application provides a method for converting special-shaped chips into standard chips for tape-out, which can make the special-shaped chips compatible with existing standardized and automated equipment, and can fully realize automated tape-out, thus solving the problems of high loss rate, large process fluctuation and low tape-out efficiency encountered by small-size chips during the tape-out process.

[0043] The process of the method of the embodiment of the present application mainly includes:

[0044] Special-shaped chip → bonding to standard substrate sheet 1 → gap filling → back side planarization → preparation of standard substrate sheet 2 → secondary bonding → debonding of standard substrate sheet 1 → conversion of special-shaped sheet into standard sheet → front-end process → debonding → dicing into die to be packaged.

[0045] In some embodiments, the first standard substrate sheet meets grinding process conditions, and the second standard substrate sheet meets temperature resistance, chemical resistance, and etching resistance requirements.

[0046] In some embodiments, the special-shaped chip is temporarily bonded to the first standard substrate sheet through a bonding medium, wherein the bonding medium is a pyrolytic bonding film and the bonding pressure is pasting at room temperature and pressure. The first standard substrate sheet of the special-shaped chip after secondary bonding is debonded, wherein the debonding meets the set temperature rate, for example, 95°C / 10min. Bonding medium: standard sheets include but are not limited to all bonding media such as bonding glue, bonding film, photoresist, and adhesive wax.

[0047] In some embodiments, performing secondary bonding on the first standard substrate sheet after dispensing and filling and the second standard substrate sheet comprises:

[0048] The bonding medium used is hot pressing bonding glue, and the bonding medium meets the temperature resistance requirement of >180°C / 30min.

[0049] Bonding media: Standard sheets include but are not limited to bonding glue, bonding film, photoresist, bonding wax and other media with bonding function.

[0050] Use one or more of acetone, ethanol, NMP, IPA, and developer chemical reagents, and meet the etching process requirements of ion implantation and etching;

[0051] Bonding process conditions: pressure: 20-40kN, bonding temperature 150-220℃ / 5-10min.

[0052] In some embodiments, after the front-end process is completed, the debonding process for debonding the special-shaped chip is laser debonding of a specified wavelength, such as laser debonding of 308 nm / 355 nm / 1064 nm.

[0053] In a specific example, the standard backing plate used in the embodiment of the present application includes, but is not limited to: 2-inch, 4-inch, 6-inch, 8-inch and 12-inch standard wafers, and standard chips of various sizes.

[0054] The process effect of the conversion method of the special-shaped sheet and the standard sheet in the embodiment of the present application is as follows: Figure 3 As shown, the method of converting special-shaped wafers into standard wafers and performing front-end process wafer taping through the present application can smoothly integrate the wafer taping process of small-size chips into automated equipment and avoid the loss of small-size chips during repeated manual clamping and transportation, thereby improving the wafer taping efficiency, greatly reducing chip losses, and improving the wafer taping consistency.

[0055] It should be noted that in the various embodiments of the present application, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "includes a ..." does not exclude the presence of other identical elements in the process, method, article or device including the element.

[0056] The serial numbers of the above-mentioned embodiments of the present application are for description only and do not represent the advantages or disadvantages of the embodiments.

[0057] The embodiments of the present application are described above in conjunction with the accompanying drawings, but the present application is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of the present application, ordinary technicians in this field can also make many forms without departing from the purpose of the present application and the scope of protection of the claims, all of which are within the protection of the present application.

Claims

1. A method for converting special-shaped sheets into standard sheets, characterized in that: include: Temporarily bonding the special-shaped chip to the first standard substrate through a bonding medium; Filling the gap between the temporarily bonded special-shaped chip and the first standard substrate with glue; preparing a second standard substrate sheet coated with a temporary bonding medium; Performing secondary bonding on the first standard substrate sheet after being filled with glue and the second standard substrate sheet; Debonding the first standard substrate sheet of the special-shaped chip after secondary bonding to form a temporary bonding standard sheet; Performing front-end process tape-out on the temporary bonded standard wafer; After the front-end process is completed, the special-shaped chip is debonded and the second standard substrate is removed to restore the special-shaped chip.

2. The method for converting special-shaped wafers and standard wafers according to claim 1, characterized in that: The first standard substrate sheet meets the grinding process conditions, and the second standard substrate sheet meets the requirements of temperature resistance, chemical resistance and etching resistance.

3. The method for converting special-shaped wafers and standard wafers according to claim 1, characterized in that: After the gap between the temporarily bonded special-shaped chip and the first standard substrate is filled with glue, the method further includes: The back side of the special-shaped chip is flattened to obtain a chip with parameters that meet the requirements.

4. The method for converting special-shaped wafers and standard wafers according to claim 2, characterized in that: Temporarily bonding the special-shaped chip to the first standard substrate through a bonding medium, wherein the bonding medium is a pyrolytic bonding film and the bonding pressure is bonding at room temperature and pressure; The first standard substrate of the special-shaped chip after secondary bonding is debonded, wherein the debonding meets a set temperature rate.

5. The method for converting special-shaped wafers into standard wafers according to claim 4, characterized in that: The second bonding of the first standard substrate sheet after the dispensing filling with the second standard substrate sheet comprises: The bonding medium is a hot-press bonding adhesive, and the bonding medium meets the temperature resistance requirement of >180℃ / 30min; and, Use one or more of acetone, ethanol, NMP, IPA, and developer chemical reagents, and meet the etching process requirements of ion implantation and etching; Bonding process conditions: pressure: 20-40kN, bonding temperature 150-220℃ / 5-10min.

6. The method for converting special-shaped wafers and standard wafers according to claim 5, characterized in that: After the front-end process is completed, the debonding process for debonding the special-shaped chip is laser debonding with a specified wavelength.

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