A method for processing a sod film
The three-step annealing process improves the density and strength of the SOD membrane, solves the problem of pores and cracks in the SOD membrane during annealing, and enhances the gap filling ability and membrane stability.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2020-10-29
- Publication Date
- 2026-03-20
AI Technical Summary
In the prior art, SOD membranes are prone to pores and cracks during the annealing process, resulting in insufficient density and affecting gap filling ability and membrane strength.
A three-step annealing process is adopted: the first low-temperature annealing involves alternating the introduction of oxygen and nitrogen at 300℃~500℃; the second low-temperature annealing involves introducing a mixture of oxygen and hydrogen at 300℃~500℃; and the third high-temperature annealing involves introducing a mixture of oxygen and hydrogen at 700℃~1100℃. This process changes the chemical properties of the SOD film, promotes the degassing of the material, and increases its density.
It effectively reduces pores, improves the density and strength of SOD membranes, enhances gap filling ability and membrane stability.
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Figure CN114429934B_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the field of semiconductor production, in particular to a processing method of SOD film. BACKGROUND
[0002] In the process of making DRAM shallow trench isolation (STI), more holes are generated when gap filling uses CVD film quality. Therefore, spin-on dielectric (SOD) film quality is used to replace CVD film to fill the gap. Since the carbon content in SOD film quality material is too much, the density is insufficient, and film quality rupture is prone to occur. Therefore, after obtaining the SOD film quality, annealing treatment is needed. The existing annealing treatment process is as shown in the following table: Figure 1 Firstly, annealing is performed at a low temperature of 300-500℃, and the annealing atmosphere is O2, H2+O2 in sequence; then annealing is performed at a high temperature of 700-1100℃, and the annealing atmosphere is O2, H2+O2 in sequence. However, this method is prone to generate new film quality (such as oxide film, etc.), and is also prone to film quality rupture due to insufficient outgassing.
[0003] Therefore, the present application is proposed. SUMMARY
[0004] The main purpose of the present application is to provide a processing method of SOD film, which can promote material outgassing to improve gap filling capacity, and can also improve SOD film density, reduce holes, and improve film strength through high-temperature annealing.
[0005] In order to achieve the above purpose, the present application provides the following technical solutions:
[0006] A processing method of SOD film, comprising:
[0007] First low-temperature annealing: alternately input oxygen gas and nitrogen gas into the SOD film at a temperature of 300-500℃;
[0008] Second low-temperature annealing: input a mixed gas of oxygen and hydrogen into the SOD film at a temperature of 300-500℃;
[0009] Third high-temperature annealing: input a mixed gas of oxygen and hydrogen into the SOD film at a temperature of 700-1100℃. Compared with the prior art, the present application uses the method of alternately inputting oxygen O2 and nitrogen N2 to change the chemical properties of SOD and increase its stress, which can promote material outgassing, improve gap filling capacity, improve SOD film density, reduce holes, and improve film strength. Through the three-step process of alternately inputting gas at low temperature, inputting H2+O2 at low temperature, and inputting H2+O2 at high temperature, the SOD film is converted into a stable film quality with high density and great strength, and the rupture phenomenon is greatly reduced.
[0010] Compared with the prior art, the present invention achieves the following technical effects:
[0011] (1) Prevent the initial rupture of the SOD membrane;
[0012] (2) Improve the ability to fill gaps;
[0013] (3) Improve the density of SOD membrane;
[0014] (4) Improve the stability of SOD film and improve stress variability. Attached Figure Description
[0015] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention.
[0016] Figure 1 This is a flowchart of the existing technology for annealing SOD film.
[0017] Figure 2 This is a flowchart of the SOD film annealing process according to the present invention. Detailed Implementation
[0018] Embodiments of the present disclosure will now be described with reference to the accompanying drawings. However, it should be understood that these descriptions are exemplary only and are not intended to limit the scope of the disclosure. Furthermore, descriptions of well-known structures and technologies are omitted in the following description to avoid unnecessarily obscuring the concepts of the present disclosure.
[0019] The accompanying drawings illustrate various structural schematics according to embodiments of the present disclosure. These drawings are not to scale, and some details have been enlarged for clarity, and some details may have been omitted. The shapes of the various regions and layers shown in the drawings, as well as their relative sizes and positional relationships, are merely exemplary and may deviate from reality due to manufacturing tolerances or technical limitations. Furthermore, those skilled in the art can design regions / layers with different shapes, sizes, and relative positions as needed.
[0020] In the context of this disclosure, when a layer / element is referred to as being "above" another layer / element, the layer / element may be directly above the other layer / element, or there may be an intermediate layer / element between them. Additionally, if a layer / element is "above" another layer / element in one orientation, then when the orientation is reversed, the layer / element may be "below" the other layer / element.
[0021] Many low-k insulating media adopt the method of silicon wafer spin coating, namely SOD, and common insulating media include methyl silsesquioxane (MSQ), hydrogen silsesquioxane (HSQ), etc.
[0022] In order to improve the rupture phenomenon of the traditional SOD film, the present application provides the following annealing method:
[0023] First low-temperature annealing: alternately input oxygen gas and nitrogen gas to the SOD film at a temperature of 300-500°C;
[0024] Second low-temperature annealing: input a mixed gas of oxygen and hydrogen to the SOD film at a temperature of 300-500°C;
[0025] Third high-temperature annealing: input a mixed gas of oxygen and hydrogen to the SOD film at a temperature of 700-1100°C.
[0026] The present application does not limit the spin coating process of the SOD film, and the spin coating conditions and film thickness are usually determined according to the device type, film purpose and process requirements.
[0027] Compared with the prior art, the present application can change the chemical properties of the SOD, increase the stress thereof, and thus on the one hand promote the material to release gas and improve the gap filling capacity, and on the other hand improve the density of the SOD film, reduce the pores and improve the film strength. Through the three-step process of alternating atmosphere low-temperature annealing, H2+O2 low-temperature annealing and H2+O2 high-temperature annealing, the SOD film is converted into a stable film with high density and great strength, and the rupture phenomenon is greatly reduced.
[0028] In some embodiments, in the step ①, the first annealing atmosphere and the last annealing atmosphere are both oxygen O2 atmosphere.
[0029] In some embodiments, the alternating gas in the step ① is in turn oxygen O2 gas, nitrogen N2 gas, oxygen O2 gas, nitrogen N2 gas and oxygen N2 gas, and the flow of the preferred embodiment is shown in Figure 2 .
[0030] In some embodiments, the total annealing time of the first low-temperature annealing is 10-120 min, so as to further improve the film density.
[0031] In some embodiments, the total annealing time of the second low-temperature annealing is 10-120 min.
[0032] In some embodiments, the total annealing time of the third high-temperature annealing is 10-120 min.
[0033] In some embodiments, the temperature ramping rate in the processing method is 3 °C / min to 10 °C / min.
[0034] In some embodiments, the annealing method can be performed in any equipment, including but not limited to a typical batch chip deposition equipment, a single chip deposition equipment, or a furnace tube deposition equipment.
[0035] In some embodiments, the SOD film can be used for STI filling in DRAM, NAND FLASH, or logic devices.
[0036] The above describes embodiments of the present disclosure. However, these embodiments are merely for illustrative purposes, and are not intended to limit the scope of the present disclosure. The scope of the present disclosure is defined by the appended claims and their equivalents. Without departing from the scope of the present disclosure, those skilled in the art can make various substitutions and modifications, which should all fall within the scope of the present disclosure.
Claims
1. A method for treating an SOD membrane, characterized in that, include: First low-temperature annealing: At a temperature of 300℃~500℃, oxygen gas and nitrogen gas are alternately introduced into the SOD membrane; Second low-temperature annealing: At a temperature of 300℃~500℃, a mixture of oxygen and hydrogen gas is introduced into the SOD membrane; Third high-temperature annealing: At a temperature of 700℃~1100℃, a mixture of oxygen and hydrogen gas is introduced into the SOD membrane.
2. The processing method according to claim 1, characterized in that, During the first low-temperature annealing, when gases are alternately introduced, both the first and last introduced gases are oxygen gases.
3. The processing method according to claim 1, characterized in that, The gases alternately introduced during the first low-temperature annealing are: oxygen gas, nitrogen gas, oxygen gas, nitrogen gas, and oxygen gas.
4. The processing method according to any one of claims 1-3, characterized in that, The total annealing time for the first low-temperature annealing is 10 min to 120 min.
5. The processing method according to claim 1, characterized in that, The total annealing time for the second low-temperature annealing is 10 min to 120 min.
6. The processing method according to claim 1, characterized in that, The total annealing time for the third high-temperature annealing is 10 min to 120 min.
7. The processing method according to claim 1, characterized in that, The heating rate in the treatment method is 3℃ / min ~ 10℃ / min.
8. The processing method according to claim 1, characterized in that, The processing method is carried out in a batch chip deposition equipment, a single chip deposition equipment, or a furnace tube deposition equipment.
9. The processing method according to claim 1, characterized in that, The SOD film is used for STI filling in DRAM, NAND FLASH or logic devices.
Citation Information
Patent Citations
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