TW498426B - Dry development method - Google Patents

Abstract

This invention provides a dry development method using bilayer resist. Firstly, a insulation layer, a first resist layer and a second resist layer are formed sequentially on a semiconductor substrate. Subsequently, after the second resist layer is developed through the conventional lithography process, the pattern on the second resist layer is transferred precisely onto the first resist layer to expose the insulation layer using oxygen, carbon monoxide and argon as reaction gases for dry development process.

Description

498426

FIELD OF THE INVENTION: Double-layer solvation The present invention relates to a lithography process technology and a dry development method of a resist, which can effectively improve the problem of lithography and rough edges of photoresist patterns. In particular, it has a resolution of a process. There is a related technical description: In the process technology of a semiconductor integrated circuit, there are: In the photoresist process technology: Because the lithography technology using soap layer green can no longer meet the future = ▲ 要 ’, the lithography technology of double-layer photoresist is gradually receiving attention. For example, Lu uses the double-layer photoresist technology and 193 nanometer (nm) exposure to increase the line width to 0.10. To further understand the present invention, the following description refers to the conventional double-layer resistance with reference to the la to id diagrams. The dry display range of the agent is 0 η. First, referring to FIG. 1a, an insulating layer 2, a first resist layer 4, and a second resist layer 6 are sequentially formed on a semiconductor substrate 10, such as a silicon wafer. Among them, the second resist layer 6 is a silicon-containing photoresist and is thinner than the first resist layer 4, and then the silicon-containing photoresist 6 in the exposed part is removed by exposure and wet development, and a second The resist pattern 6a is shown in FIG. 1b. At this time, reactive ion etching (RIE) is performed with an oxygen plasma. Since the silicon-containing photoresist pattern 6 & will form silicon dioxide, the first resist layer 4 underneath is protected from being etched. And the unprotected part will be decomposed by the plasma to form the first resist pattern 4a. As shown in Figure lc, this step is called "dry development". The advantage of this process is that A resist layer

0503-6504W; TSMC2001-0397; spin.ptd Page 4 498426

Shangguan has fct * -r oxide stone Xibao β-mangan ’, so it will be able to obtain a high aspect rati0 pattern in the subsequent remaining processes. In terms of resolution, due to the wish of the photoresist containing the photoresist 6 coating; 而 ρ 私 # ^ However, the lateral direction of the oxygen polymerization: strong and the figure Λ = can / liter. However, (π and 刎 are strong, and the photoresist pattern edge profile (Pr0flle) is not good, as shown in Figure lc. B, = this, in June with reference to Figure 1 d, removing After the second resist pattern 6a, the cap ^ main one resist pattern 4 & is used as a engraved mask to form the insulation layer 2 to form = 3, because the first resist pattern "is poor in outline, resulting in a trench 3

Gallery f, and guide, critical dimension (CD

= Easy to control. Although the plasma etching effect can be improved by performing oxygen plasma etching at a low temperature, the process is complicated and the production cost is high. σ Α is fi. There are also conventional methods to use sulfur dioxide (SO2) and oxygen as the etching reaction gas to improve the side etching effect. However, the shape of the reaction chamber is not easy to control, resulting in poor process stability and poor product reproducibility. High defect = such as and after the dry development of the stone-containing photoresist pattern, its edge contour is non-rough. Since the double-layer photoresist process is likely to be the most important photoresist technology for integrated circuits in the future, it is necessary to improve the above problems. In view of this, the main object of the present invention is to provide a

In the shadow method, by using carbon monoxide gas, oxygen and argon as reaction gases for dry shirts, the resolution is effectively improved and the problem of rough edges of the pattern is solved. Summary of the invention: The object of the present invention is to provide a dry development with a double-layer resist.

498426

Method in order to obtain better resolution in the lithography process, thereby having better lithography process tolerance (process window) and easy control of critical dimension (CD). Another development method of the present invention, In order to solve the problem, according to the above-mentioned eye-type development method, the invention is suitable for providing a rough edge of the resist pattern. The present invention provides a semiconductor substrate, an insulating layer is formed on the substrate, and a surface of a second resist is formed by a first resist The body, oxygen, and other problems in completing the recovery reaction chamber include a lower layer and a dose pattern and a resist surface, which are used to complete a reactant layer, and the electrical first resist pattern is patterned with argon gas. Initially, the surface of the first exposed insulation layer exposed by the formation of a second resist slurry is used as a reaction gas. After borrowing, the state is included. Dry type of double-layer resist 〇 Dry step with double-layer resist: Step on the second resist layer in sequence; the surface of the first resist layer is exposed to form a pattern of carbon monoxide gas transfer in the middle. Room cleanup steps to

Brief description of the drawings: In order to make the above-mentioned objects, features, and advantages of the present invention more comprehensible, the following describes the preferred embodiments in detail with the accompanying drawings, as follows: Figures 1 a to 1 d Figure 2 shows a conventional dry development method with a double-layer resist; Figures 2a to 2e show a dry development method with a double-layer P and agent according to the first embodiment of the present invention; Figures 3a to 3e The drawing shows a dual-portion device according to a second embodiment of the present invention.

498426 V. Description of the invention (4) Dry development method of layer resist [Symbol description] 2, 1 0 2, 2 0 2 ~ insulation layer; 3, 103 ~ groove; 4, 1 0 4, 2 0 4 ~ first A resist layer; 4a, 104a, 204a ~ first resist pattern 6, 106, 2 06 ~ second resist layer; 6a, 206, 206a ~ second resist pattern; 10, 100, 200 ~ Semiconductor substrate; 201 ~ stop layer; 203 ~ via hole; 203a ~ contact window. Detailed description of the preferred embodiment: The first embodiment of the present invention is described and is applied to a subsequent etching process to form a trench for a dry development method with reference to Figures 2a to 2e. First, please refer to FIG. 2a, provide a semiconductor substrate 100, such as a silicon wafer, and then sequentially form an insulating layer 102, a first resist layer 104, and a first substrate on the substrate 100. Two resist layer 106. The first resist layer 104 is a silicon-free organic photoresist, and the thickness is in the range of 100 to 5000 angstroms (person). The second resist layer 106 is a silicon-containing organic photoresist. Resistance, suitable for exposure light source with a wavelength of 193 nanometers (nm), which is thinner than the first resist layer 0503-6504T ^ if; TSMC2001-0397; spin.ptd page 7 498426

5. Description of the invention (5) 104 and in the range of 500 to 3000 Angstroms (A). Next, "eyes refer to Figure 2b", by the conventional lithography technology, for example, argon fluoride (ArF) 193nm laser deep ultraviolet (DUV) is used as the exposure light source 'and the first method is formed by a wet development method. The resist pattern 106a and exposes the surface of the first resist 104. Next, the exposed surface of the first resist 104 is dry-developed by one of an inductively coupled plasma (ICP) method and a transformer coupled plasma (TCP) method to form a dry surface. The first resist pattern 104a is parallel to the surface of the insulating layer 102. That is, the surface of the first resist 104, which is exposed by a dual radio frequency (duai ^ F) power engraving machine, is engraved with plasma money, in which one radio frequency power is used to generate plasma and the other radio frequency power is used to control ion bombardment. (Ion bombardment). In this embodiment, the dry development process uses carbon dioxide (C0), oxygen (02), and argon (Ar) as the etching reaction gas 2, wherein the flow rate of carbon monoxide is in the range of 10 to 5000 sccm; oxygen The flow rate is in the range of 1 to 50 ㈣㈣; the flow rate of argon is in the range of 50 to 1 000 seem and the% flow rate: co flow rate is maintained at a ratio of 1: ιιιο〇. In this way, the second resist pattern can be smoothly transferred to the first resist layer 104 / as shown in FIG. 2c, and the conventional method is improved (that is, only oxygen is used as a reactive gas for dry development). Disadvantages of performing under low temperature process and still maintain the advantages of dry development, that is, have better analysis of the dry display and 2e diagram of the present invention. After removing the second resist pattern 1 0 4 a as a shadow mask, ’Next, please refer to 2d case 1 06a, and then use the first resist to touch the surface of the insulating layer 102 to form a

Description of the invention (6) Trenches 1 0 3. Because of the exhaustion of the above-mentioned ratio of exhaustion, because of & can effectively solve the resist map, carbon monoxide gas as a better profile. 3Finally, the problem of rough edges on the picture is achieved to complete the transfer of the pattern. ^ Remove the first resist pattern with moxibustion ^ After the transfer of the case is completed, you can then proceed to the reaction chamber, that is, remove the deposits deposited in the reaction and expand it by using the electrical process in the process. For example, the organic polymer formed in the manufacturing process is used to maintain the reproducibility of the stable product in the initial clean state of the chamber. ^ Referring to Figure 3af ^ e, the second embodiment of the present invention has two features: The dry development method of the resist is applied to a contact window in the subsequent etching process. First, please refer to FIG. 3a to provide a semiconductor substrate 200, such as a silicon wafer, on which a semiconductor element is formed (not shown). Then, a termination layer 201, an insulating layer go ?, a first resist layer 204, and a second resist layer 206 are sequentially formed on the substrate 200. Among them, the first and second resist layers 204 and The material and thickness of the second resist layer 206 are the same as in the first embodiment, and will not be repeated here. Next, referring to FIG. 3b, the second resist pattern 20 is also formed by the method of the first embodiment. 6 a and exposed the surface of the first resist 2 04. Then, 'inductive One of the plasma method (ICP) and the transformer-coupled plasma method (TCP) is used to dry develop the exposed surface of the first resist 205 ′ to form a first resist pattern 204a and expose the surface of the insulating layer 202. In the second embodiment, the dry development process is similarly performed with carbon monoxide (c0),

0503-6504TWf; TSMC2001-0397; spin.ptd 498426 V. Description of the invention (7) Oxygen (02) and argon (Ar) are used as etching reaction gases, as described in the first embodiment. Among them, the flow rate of carbon monoxide is in the range of 10 to 5000 sccm, the flow rate of oxygen is in the range of 1 to 50 seem; the flow rate of argon is in the range of 50 to 1,000 seem, and 〇2: c〇 is maintained at i : The ratio of i oq 〇〇. In this way, the advantages of the first embodiment can be obtained, as shown in the figure. Similarly, after completing the dry development of the present invention, please refer to FIG. 3d. After removing the second resist pattern 206 & After that, the first resist pattern 204a is used as a mask to etch the surface of the insulating layer to form a via hole 203 and expose the surface of the termination layer 20. Because the above proportions of oxygen and carbon monoxide gas are used as The reactive gas is etched, so that the via hole 2 with a better profile is obtained in the same way. Most, 'Please refer to FIG. 3e, after removing the first resist pattern 1043', and then remove the exposed termination layer 2. 1 surface and exposed the 2000 surface of the substrate to complete the production of the contact window 203a. As in the first embodiment, after the pattern transfer is completed, the reaction chamber can be cleaned to maintain the stability of the process and the reproducibility of the product. As described above 'According to the dry development method of the present invention, it can effectively improve the resolution, has better process tolerance, and is easy to control the key graphic size (CD), and effectively solves the rough edges of the photoresist pattern. The problem is to obtain better grooves and contact windows for the corridor. Therefore, it can be applied to the lithography process of integrated circuits with high integration and the shallow trench isolation (STI) process and inlay. (Damascene) process. Although the present invention has been disclosed as above with preferred embodiments, it is not intended to limit the present invention. 'Any person skilled in the art will not depart from the essence of the present invention.

Page 10 498426 V. Description of the invention (8) Within the scope of God and God, modifications and retouching can be made. Therefore, the scope of protection of the present invention shall be determined by the scope of the attached patent application. ΙΒΙ 0503-6504TWf; TSMC2001-0397; spin.ptd p. 11

Claims (1)

498426 Suitable for a semiconductor 1. A dry development substrate with a double-layer resist, comprising the following steps: a first resist layer and a first sequentially forming an insulating layer and a resist layer on the substrate; the first patterning The second resist layer to form a surface of a resist layer; and a second resist pattern and exposing the plasma to expose the surface of the first resist layer to form a first resist pattern and expose the In the surface of the insulating layer, carbon monoxide gas and oxygen gas are used as reaction gases to complete the pattern transfer. 2. The dry development method according to item 1 of the scope of the patent application, wherein after removing the first resist pattern, a reaction chamber cleaning step is further included to restore the initial state of the reaction chamber. 3. The dry development method according to item 1 of the scope of the patent application, wherein the first resist layer is an organic photoresist containing no silicon. 4. The dry development method as described in item 1 of the scope of the patent application, wherein the second resist layer is an organic light P denier containing silicon. 5. The dry development method as described in item 1 of the scope of the patent application, wherein the first resist layer is etched by plasma using one of an induction peeling plasma method and a transformer coupling electropolymerization method. 6. The dry development method according to item 1 of the scope of the patent application, wherein the flow rate of the carbon monoxide gas is in a range of 10 to 5000 sccm. 7. The dry development method described in item 1 of the scope of patent application, wherein the oxygen consumption is between 1 and 50 s c c m. 8. The dry development method described in item 1 of the scope of patent application, where more 0503-6504Bff; TSMC2001-0397; spin.ptd State 426 Sixth, an argon gas is used as the reaction gas in the scope of the patent application. 9. According to the dry development method described in item 3 of the scope of patent application, the thickness of the first resist layer In the range of 1000 to 5000 Angstroms. 10. The dry development method as described in item 4 of the scope of patent application, wherein the thickness of the second resist layer is in the range of 500 to 3000 angstroms. X & ^ 1 1 The dry development method according to item 8 of the scope of patent application, wherein the chlorine gas / claw house is in a range of 50 to; [00 00 s c c m. 0503-6504TW; TSMC2001 -0397; spinptt page 13