Low-k film damage-resistant CO chemistry-based ash process for low-k/Cu interconnection in flash memory devices

Lee, Jeongyun; Park, Wanjae; Kim, Dong Hwan; Choi, Jungdong; Shin, Ki Soon; Chung, Ilsub

doi:10.1016/j.tsf.2009.01.152

Cited by 8 publications

(5 citation statements)

References 7 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…37 Although pure H 2 plasmas can significantly minimize damage, the rate of removal of PR is relatively slow. 38 Increasing substrate temperature to increase the rate of PR removal is an option; however, the increase in temperature also increases the rate of carbon removal. 39 To speed the rate of PR removal, N 2 or Ar can be mixed with H 2 .…”

Section: Comparison Of Trends With Prior Workmentioning

confidence: 99%

“…However, the increase in removal rate is small. 38,39 As a result, alternative chemistries are also being investigated for plasma ashing of PR, among them being the use of CO 2 , which produces plasmas capable of stripping PR at acceptable rates while not appreciably damaging the low-k material. 40 CO 2 (or CO) based plasmas have been reported to produce a significantly thinner damage layer compared to O 2 plasmas when removing the same thickness of PR.…”

Section: Comparison Of Trends With Prior Workmentioning

confidence: 99%

See 1 more Smart Citation

Damage by radicals and photons during plasma cleaning of porous low-k SiOCH. II. Water uptake and change in dielectric constant

Shoeb

Kushner

2012

Journal of Vacuum Science &Amp; Technology A: Vacuum, Surfaces, and Films

View full text Add to dashboard Cite

Porous dielectric materials offer lower capacitances that reduce RC time delays in integrated circuits. Typical porous low dielectric (low-k) materials include SiOCH-silicon dioxide with carbon groups, principally-CH 3 , lining the pores. Fluorocarbon plasmas are often used to etch such low-k materials. These processes leave a fluorocarbon polymer on the SiOCH surface that must be removed, often with oxygen or hydrogen containing plasmas. Pores open to the surface and that are internally connected provide pathways for reactive species to enter into the porous network and produce damage. For example, during cleaning using O 2 containing plasmas, reactions of O atoms with-CH 3 groups can increase the k-value by removing C atoms. Vacuum ultraviolet (VUV) photons produced by the plasma and that penetrate into the material can scission-Si-CH 3 bonds and accelerate the removal of-CH 3 groups. This paper reports on results from a computational investigation of Ar/O 2 and He/H 2 plasma cleaning of porous SiOCH when including the effects of VUV photons. The authors found that He/H 2 plasmas are able to clean CF x polymers deposited during etching while producing milder damage to underlying-CH 3 sites compared to O 2 plasmas due to the lower reactivity of H atoms and the shorter penetration distance of photons produced in He/H 2 plasmas. V

show abstract

Section: Comparison Of Trends With Prior Workmentioning

confidence: 99%

Section: Comparison Of Trends With Prior Workmentioning

confidence: 99%

Damage by radicals and photons during plasma cleaning of porous low-k SiOCH. II. Water uptake and change in dielectric constant

Shoeb

Kushner

2012

Journal of Vacuum Science &Amp; Technology A: Vacuum, Surfaces, and Films

View full text Add to dashboard Cite

show abstract

“…Acceptable resist etch rates (100 nm/min) can be achieved by using a high temperature (260°C) downstream H 2 plasma. The CO-or CO 2 -based resist strip approaches are generally run in RIE tools [55,65,66]. The downstream H 2 plasma only reacts with H in the low-k film, in a replacement reaction, without altering the stoichiometry of the film [64].…”

Section: Dielectric Patterningmentioning

confidence: 99%

Process Technology for Copper Interconnects

Gambino

2012

Handbook of Thin Film Deposition

View full text Add to dashboard Cite

“…Hence, resist strips with low damage must be used with the multilayer resist approach. There are two different approaches for resist strip for low-k materials; downstream H 2 chemistry [18,[22][23][24] and CO-or CO 2 -based reactive ion etching (RIE) [14,25,26]. Direct exposure of the low-k materials to O 2 , N 2 , or H 2 plasmas (i.e., with ion bombardment) causes significant damage [22], with more damage for porous materials compared to non-porous materials.…”

Section: Dielectric Film Patterningmentioning

confidence: 99%

“…The CO or CO 2 -based resist strip approaches are generally run in RIE tools [14,25,26]. Argon is often added to the strip chemistry and a bias is applied to the wafer to enable a high removal rate of resist [26].…”

Section: Dielectric Film Patterningmentioning

confidence: 99%

Process Challenges for Integration of Copper Interconnects with Low-k Dielectrics

Gambino¹

2011

ECS Trans.

View full text Add to dashboard Cite

Copper interconnects have gained wide acceptance in the microelectronics industry due to improved resistivity and reliability compared to Al interconnects. Initially SiO2 was used as the interlevel dielectric. To reduce interconnect capacitance, C-doped SiO2 or SiCOH was introduced at the 90 nm node, and porous SiCOH was introduced at the 45 nm node, to achieve a dielectric constant of 2.5 or less. However, there are many process problems with the integration of Cu interconnects and porous low-k dielectrics, including patterning, liner coverage, chemical mechanical polishing (CMP), and packaging. In this paper, some of the key integration challenges are discussed.

show abstract

Low-k film damage-resistant CO chemistry-based ash process for low-k/Cu interconnection in flash memory devices

Cited by 8 publications

References 7 publications

Damage by radicals and photons during plasma cleaning of porous low-k SiOCH. II. Water uptake and change in dielectric constant

Damage by radicals and photons during plasma cleaning of porous low-k SiOCH. II. Water uptake and change in dielectric constant

Process Technology for Copper Interconnects

Process Challenges for Integration of Copper Interconnects with Low-k Dielectrics

Contact Info

Product

Resources

About