US5378318A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Planarization
Assignee: NXP BV
•
Filing: 1992-06-05
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Granted: 1995-01-03
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Expires: 2012-06-05
Abstract
Abstract A method for improved planarization of surface topographies encountered in semiconductor processing that involve the etch-back of exposed surfaces of an oxide of silicon and a spin-on-glass. The oxide of silicon is chosen to be oxygen-deficient and thus silicon-rich, with a spectroscopically-defined silicon richness coefficient CSR that is greater than 0, and preferably greater than 0.005. A fluorine-containing process gas such as CHF3 combined with one or more of CF4, C2F6 and SF6 can be used in the etch chemistry. Sensitivity of the etch rate to certain parameters, such as the relative surface area of the exposed oxide of silicon and the fraction of fluorine present, is either reduced or eliminated. Improvement and better control of planarization is achieved by the process, resulting in a widening of the etch-back process window.
Inventors
- 👤 Milind Weling
- 👤 Vivek Jain
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 17:07
CPC Classifications
H; H10; H10P; H10P50/00; H10P50/20; H10P50/28; H10P50/282; H10P50/283; H10W; H10W20/00; H10W20/01; H10W20/071; H10W20/092
Claims Analysis
Total Claims: 54
Claim 1
Independent Claim
62 words
A method for improved planarization comprising the steps of: providing a patterned structure of material containing at least one exposed surface of non-stoichiometric, silicon-rich-oxide (SRO) and at least one exposed surface of a spin-on-material; and etching said patterned structure with a fluorine-containing process gas; whereby the etch rates of the exposed surfaces of said silicon-rich-oxide and said spin-on-material are about the same.
Claim 2
Independent Claim
62 words
A method for improved planarization comprising the steps of: providing a patterned structure of material containing at least one exposed surface of non-stoichiometric, silicon-rich-oxide (SRO) and at least one exposed surface of a spin-on-material; and etching said patterned structure with a fluorine-containing process gas; whereby the etch rates of the exposed surfaces of said silicon-rich-oxide and said spin-on-material are about the same.
Claim 3
Dependent Claim
22 words
The method of claim 1, further comprising the step of choosing said silicon-rich-oxide with a silicon richness coefficient CSR greater than zero.
Claim 4
Dependent Claim
22 words
The method of claim 1, further comprising the step of choosing as said process gas a gas that contains essentially no oxygen.
Claim 5
Dependent Claim
17 words
The method of claim 1, further comprising the step of including CHF 3 in said process gas.
Claim 6
Dependent Claim
24 words
The method of claim 4, further comprising the step of including another fluorine-containing gas in addition to said CHF 3 in said process gas.
Claim 7
Dependent Claim
43 words
The method of claim 5, further comprising the step of choosing as said process gas a mixture of a gas containing CHF 3 and a gas selected from the group consisting of CF 4 , C 2 F 6 and SF 6 .
Claim 8
Dependent Claim
23 words
The method of claim 1, further comprising the step of selecting said silicon-rich oxide so that its refractive index is greater than 1.46.
Claim 9
Dependent Claim
50 words
The method of claim 1, further comprising the step of selecting said process gas so that the selectivity of said spin-on-material relative to said silicon-rich-oxide, defined as the ratio of etch rate of the spin-on-material divided by the etch rate of the silicon-rich-oxide in a patterned structure, is approximately 1.
Claim 10
Dependent Claim
18 words
The method of claim 1, further comprising the step of forming said silicon-rich oxide by a PECVD process.
Claim 11
Dependent Claim
24 words
The method of claim 1, wherein said spin-on-material is drawn from a class of semiconductor processing materials consisting of spin-on-glass, polyimide and photoresist material.
Claim 12
Dependent Claim
28 words
The method of claim 10, further comprising the steps of selecting spin-on-glass as said spin-on-material and selecting said spin-on-glass from the group consisting of siloxane and silicate-based glass.
Claim 13
Dependent Claim
26 words
The method of claim 1, further comprising the step of performing said etching step at a temperature T p of between 50° C. and 250° C.
Claim 14
Independent Claim
153 words
A method for improved planarization of a patterned structure of material containing exposed surfaces of an oxide of silicon (OS) and a spin-on-material (SOM) by choice of a desired selectivity S(SOM;OS), defined as the ratio of the etch rate of the SOM divided by the etch rate of the OS, the method comprising the steps of: providing a patterned structure of material containing at least one exposed surface of a OS and at least one exposed surface of SOM, wherein the OS has a silicon richness coefficient CSR greater than zero; providing a process gas containing fluorine for etching the patterned layer; selecting a desired selectivity S(SOM;OS) for the SOM and OS materials contained in the patterned structure; etching the patterned layer with the process gas; and adjusting the silicon richness coefficient and the fraction of fluorine contained in the process gas to obtain the desired selectivity when the patterned structure is etched.
Claim 15
Independent Claim
153 words
A method for improved planarization of a patterned structure of material containing exposed surfaces of an oxide of silicon (OS) and a spin-on-material (SOM) by choice of a desired selectivity S(SOM;OS), defined as the ratio of the etch rate of the SOM divided by the etch rate of the OS, the method comprising the steps of: providing a patterned structure of material containing at least one exposed surface of a OS and at least one exposed surface of SOM, wherein the OS has a silicon richness coefficient CSR greater than zero; providing a process gas containing fluorine for etching the patterned layer; selecting a desired selectivity S(SOM;OS) for the SOM and OS materials contained in the patterned structure; etching the patterned layer with the process gas; and adjusting the silicon richness coefficient and the fraction of fluorine contained in the process gas to obtain the desired selectivity when the patterned structure is etched.
Claim 16
Dependent Claim
22 words
The method of claim 13, further comprising the step of choosing said silicon-rich-oxide with a silicon richness coefficient CSR greater than zero.
Claim 17
Dependent Claim
22 words
The method of claim 13, further comprising the step of choosing as said process gas a gas that contains essentially no oxygen.
Claim 18
Dependent Claim
17 words
The method of claim 13, further comprising the step of including CHF 3 in said process gas.
Claim 19
Dependent Claim
24 words
The method of claim 16, further comprising the step of including another fluorine-containing gas in addition to said CHF 3 in said process gas.
Claim 20
Dependent Claim
43 words
The method of claim 17, further comprising the step of choosing as said process gas a mixture of a gas containing CHF 3 and a gas selected from the group consisting of CF 4 , C 2 F 6 and SF 6 .
Claim 21
Dependent Claim
23 words
The method of claim 13, further comprising the step of selecting said silicon-rich oxide so that its refractive index is greater than 1.46.
Claim 22
Dependent Claim
50 words
The method of claim 13, further comprising the step of selecting said process gas so that the selectivity of said spin-on-material relative to said silicon-rich-oxide, defined as the ratio of etch rate of the spin-on-material divided by the etch rate of the silicon-rich-oxide in a patterned structure, is about 1.
Claim 23
Dependent Claim
18 words
The method of claim 13, further comprising the step of forming said silicon-rich oxide by a PECVD process.
Claim 24
Dependent Claim
24 words
The method of claim 13, wherein said spin-on-material is drawn from a class of semiconductor processing materials consisting of spin-on-glass, polyimide and photoresist material.
Claim 25
Dependent Claim
28 words
The method of claim 22, further comprising the steps of selecting spin-on-glass as said spin-on-material and selecting said spin-on-glass from the group consisting of siloxane and silicate-based glass.
Claim 26
Dependent Claim
26 words
The method of claim 13, further comprising the step of performing said etching step at a temperature T p of between 50° C. and 250° C.
Claim 27
Independent Claim
95 words
A method for control of the micro-loading effect in a patterned structure of material containing exposed surfaces of an oxide of silicon and a spin-on-material, the method comprising the steps of: providing a patterned structure of material containing at least one exposed surface of silicon-rich-oxide (SRO) with a silicon richness coefficient CSR greater than zero and at least one exposed surface of spin-on-material; and etching the patterned structure with a fluorine-containing process gas; whereby the etch rates of the exposed surfaces of the silicon-rich-oxide and the spin-on-material are about equal during the time etching occurs.
Claim 28
Independent Claim
95 words
A method for control of the micro-loading effect in a patterned structure of material containing exposed surfaces of an oxide of silicon and a spin-on-material, the method comprising the steps of: providing a patterned structure of material containing at least one exposed surface of silicon-rich-oxide (SRO) with a silicon richness coefficient CSR greater than zero and at least one exposed surface of spin-on-material; and etching the patterned structure with a fluorine-containing process gas; whereby the etch rates of the exposed surfaces of the silicon-rich-oxide and the spin-on-material are about equal during the time etching occurs.
Claim 29
Dependent Claim
22 words
The method of claim 25, further comprising the step of choosing as said process gas a gas that contains essentially no oxygen.
Claim 30
Dependent Claim
17 words
The method of claim 25, further comprising the step of including CHF 3 in said process gas.
Claim 31
Dependent Claim
24 words
The method of claim 25, further comprising the step of including another fluorine-containing gas in addition to said CHF 3 in said process gas.
Claim 32
Dependent Claim
43 words
The method of claim 27, further comprising the step of choosing as said process gas a mixture of a gas containing CHF 3 and a gas selected from the group consisting of CF 4 , C 2 F 6 and SF 6 .
Claim 33
Dependent Claim
23 words
The method of claim 25, further comprising the step of selecting said silicon-rich oxide so that its refractive index is greater than 1.46.
Claim 34
Dependent Claim
50 words
The method of claim 25, further comprising the step of selecting said process gas so that the selectivity of said spin-on-material relative to said silicon-rich-oxide, defined as the ratio of etch rate of the spin-on-material divided by the etch rate of the silicon-rich-oxide in a patterned structure, is about 1.
Claim 35
Dependent Claim
18 words
The method of claim 25, further comprising the step of forming said silicon-rich oxide by a PECVD process.
Claim 36
Dependent Claim
24 words
The method of claim 25, wherein said spin-on-material is drawn from a class of semiconductor processing materials consisting of spin-on-glass, polyimide and photoresist material.
Claim 37
Dependent Claim
28 words
The method of claim 33, further comprising the steps of selecting spin-on-glass as said spin-on-material and selecting said spin-on-glass from the group consisting of siloxane and silicate-based glass.
Claim 38
Dependent Claim
26 words
The method of claim 25, further comprising the step of performing said etching step at a temperature T p of between 50° C. and 250° C.
Claim 39
Independent Claim
109 words
A method for reduction of the effect on selectivity of fluorine content in an etchant gas containing fluorine that is used to etch a patterned structure of material containing exposed surfaces of an oxide of silicon and a spin-on-material, the method comprising the steps of: providing a patterned structure of material containing at least one exposed surface of silicon-rich-oxide (SRO) with a silicon richness coefficient CSR greater than zero and at least one exposed surface of spin-on-material; and etching the patterned structure with a fluorine-containing process gas; whereby the etch rates of the exposed surfaces of the silicon-rich-oxide and the spin-on-material are about equal during the time etching occurs.
Claim 40
Independent Claim
109 words
A method for reduction of the effect on selectivity of fluorine content in an etchant gas containing fluorine that is used to etch a patterned structure of material containing exposed surfaces of an oxide of silicon and a spin-on-material, the method comprising the steps of: providing a patterned structure of material containing at least one exposed surface of silicon-rich-oxide (SRO) with a silicon richness coefficient CSR greater than zero and at least one exposed surface of spin-on-material; and etching the patterned structure with a fluorine-containing process gas; whereby the etch rates of the exposed surfaces of the silicon-rich-oxide and the spin-on-material are about equal during the time etching occurs.
Claim 41
Dependent Claim
22 words
The method of claim 36, further comprising the step of choosing as said process gas a gas that contains essentially no oxygen.
Claim 42
Dependent Claim
17 words
The method of claim 36, further comprising the step of including CHF 3 in said process gas.
Claim 43
Dependent Claim
24 words
The method of claim 38, further comprising the step of including another fluorine-containing gas in addition to said CHF 3 in said process gas.
Claim 44
Dependent Claim
43 words
The method of claim 38, further comprising the step of choosing as said process gas a mixture of a gas containing CHF 3 and a gas selected from the group consisting of CF 4 , C 2 F 6 and SF 6 .
Claim 45
Dependent Claim
23 words
The method of claim 36, further comprising the step of selecting said silicon-rich oxide so that its refractive index is greater than 1.46.
Claim 46
Dependent Claim
50 words
The method of claim 36, further comprising the step of selecting said process gas so that the selectivity of said spin-on-material relative to said silicon-rich-oxide, defined as the ratio of etch rate of the spin-on-material divided by the etch rate of the silicon-rich-oxide in a patterned structure, is about 1.
Claim 47
Dependent Claim
18 words
The method of claim 36, further comprising the step of forming said silicon-rich oxide by a PECVD process.
Claim 48
Dependent Claim
24 words
The method of claim 36, wherein said spin-on-material is drawn from a class of semiconductor processing materials consisting of spin-on-glass, polyimide and photoresist material.
Claim 49
Dependent Claim
28 words
The method of claim 44, further comprising the steps of selecting spin-on-glass as said spin-on-material and selecting said spin-on-glass from the group consisting of siloxane and silicate-based glass.
Claim 50
Dependent Claim
26 words
The method of claim 36, further comprising the step of performing said etching step at a temperature T p of between 50° C. and 250° C.
Claim 51
Dependent Claim
33 words
The method of claim 1 wherein the composition of said SRO is selected to produce an etch rate of said SRO which is about the same as the etch rate of said spin-on-material.
Claim 52
Dependent Claim
34 words
The method of claim 1 wherein the composition of said process gas is selected to produce an etch rate of said SRO which is about the same as the etch rate of said spin-on-material.
Claim 53
Dependent Claim
55 words
The method of claim 1 wherein the selectivity of said patterned structure is about the same as the selectivity of an unpatterned structure of material containing at least one exposed surface of an exposed surface of non-stoichiometric, silicon-rich-oxide (SRO) and at least one exposed surface of a spin-on-material due to the composition of said SRO.
Claim 54
Dependent Claim
15 words
The method of claim 2 wherein said CSR is greater than or equal to 0.005.
References Cited (Backward Citations)
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