High Accuracy 65nm OPC Verification: Full Process Window Model vs. Critical Failure ORC

It is becoming more and more difficult to ensure robust patterning after OPC due to the continuous reduction of layout dimensions and diminishing process windows associated with each successive lithographic generation. Lithographers must guarantee high imaging fidelity throughout the entire range of normal process variations. The techniques of Mask Rule Checking (MRC) and Optical Rule Checking (ORC) have become mandatory tools for ensuring that OPC delivers robust patterning. However the first method relies on geometrical checks and the second one is based on a model built at best process conditions. Thus those techniques do not have the ability to address all potential printing errors throughout the process window (PW). To address this issue, a technique known as Critical Failure ORC (CFORC) was introduced that uses optical parameters from aerial image simulations. In CFORC, a numerical model is used to correlate these optical parameters with experimental data taken throughout the process window to predict printing errors. This method has proven its efficiency for detecting potential printing issues through the entire process window [1]. However this analytical method is based on optical parameters extracted via an optical model built at single process conditions. It is reasonable to expect that a verification method involving optical models built from several points throughout PW would provide more accurate predictions of printing errors for complex features. To verify this approach, compact optical models similar to those used for standard OPC were built and calibrated with experimental data measured at the PW limits. This model is then applied to various test patterns to predict potential printing errors. In this paper, a comparison between these two approaches is presented for the poly layer at 65 nm node patterning. Examples of specific failure predictions obtained separately with the two techniques are compared with experimental results. The details of implementing these two techniques on full product layouts are also included in this study

Process Window OPC Verification: Dry versus Immersion Lithography for the 65 nm node

Ensuring robust patterning after OPC is becoming more and more difficult due to the continuous reduction of layout dimensions and diminishing process windows associated with each successive lithographic generation. Lithographers must guarantee high imaging fidelity throughout the entire range of normal process variations. To verify the printability of a design across process window, compact optical models similar to those used for standard OPC are used. These models are calibrated from experimental data measured at the limits of the process window. They are then applied to the design to predict potential printing failures. This approach has been widely used for dry lithography. With the emergence of immersion lithography in production in the IC industry, the predictability of this approach has to be validated on this new lithographic process. In this paper, a comparison between the dry lithography process model and the immersion lithography process model is presented for the Poly layer at 65 nm node patterning. Examples of specific failure predictions obtained separately with the two processes are compared with experimental results. A comparison in terms of process performance will also be a part of this study

Through-process window resist modelling strategies for the 65 nm node

Ensuring robust patterning after OPC is becoming more and more difficult due to the continuous reduction of layout dimensions and diminishing process windows associated with each successive lithographic generation. Lithographers must guarantee high imaging fidelity throughout the entire range of normal process variations. As a result, post-OPC verification methods have become indispensable tools for avoiding pattern printing issues. The majority of these methods are primarily based on lithographic simulations of pattern printing behaviour across dose and focus variations. The models used for these simulations are compact optical models combined with one single resist model. Even if very predictive resist models exist, they have often a large number of parameters to fit and suffer from long computing times to execute the simulations. Simplified resist models are thus needed to enhance run-time computing during simulation. The objective of this study is to test the predictability of such resist models across the process window. Two different resist models will be considered in this study. The first resist model is a pure variable threshold resist model. The second resist modelling approach is a simplified physical model which uses Gaussian convolutions and a constant threshold to model resist printing behaviour. The study concentrates on poly layer patterning for the 65 nm node. Examples of specific simulations obtained with the two different techniques are compared against experimental results

La littérature dépliée

Quand la notion d’intertextualité est apparue à la fin des années 1960, elle s’inscrivait dans une « théorie du texte » insistant sur la « productivité » de l’écriture et la signifiance comme « procès ». Instituée en catégorie générale par ses promoteurs, elle ne prétendait pas constituer un instrument critique, mais participait d’un projet philosophique. Plus tard, quand l’intertexte a commencé à faire l’objet de descriptions dans une visée poéticienne, la critique littéraire y a gagné des concepts opératoires ; elle y a peut-être perdu les perspectives générales que la théorie du texte cherchait à imposer. En se proposant de travailler sur trois mots – reprise, répétition, réécriture – les comparatistes ont voulu relancer l’intérêt pour l’intertextualité en ce début de XXIe siècle où cette notion, employée dans un contexte très éloigné de celui où elle a vu le jour, semble avoir perdu de son pouvoir de questionnement. Or toute étude comparatiste la convoque nécessairement, même si cela reste implicite, au point qu’on oublie de s’interroger sur son sens. Combien d’études de source ou d’influence se sont-elles masquées depuis vingt-cinq ans sous le vocabulaire de l’intertextualité ? Ces trois mots évoquent trois types de lecture des rapports que les œuvres d’art entretiennent avec d’autres œuvres d’art. Le premier est métaphorique : si texte veut dire tissu, comme on le dit couramment depuis Barthes, sa reprise suggère à la fois les fortunes et infortunes de sa réception (accrocs, raccords, raccommodages…) et la nécessité de toujours remettre l’ouvrage sur le métier ; il insiste sur le fait que toujours déjà tout est dit et que pourtant, sans cesse, le langage se réinvente. Le second est pratique et herméneutique : que la répétition porte sur des unités de discours plus ou moins grandes, ou qu’elle renvoie, dans une autre acception, au travail théâtral, elle suppose toujours un usage réfléchi de la langue et implique une transformation, même minimale, de l’énoncé. Le Pierre Ménard de Borges est ici l’exemple canonique ; la répétition interroge paradoxalement l’histoire : que s’est-il passé entre ses deux occurrences pour qu’un énoncé soit devenu différent de lui-même ? Le troisième est scriptural et critique : la réécriture renvoie aux opérations multiples qu’un texte effectue toujours sur d’autres textes et dont on peut entreprendre le repérage et le classement. Les quarante-et-une études de ce volume s’attachent à ces trois perspectives par lesquelles se décrit l’infini travail de pliage et de dépliage en quoi consiste l’écriture

Predictors of surgical outcomes of minimally invasive right colectomy: the MERCY study

PURPOSE: The optimal approach for minimally invasive (MIS) right colectomy remains under debate. This study aimed to describe surgical trends in the treatment of nonmetastatic right colon cancer and to identify predictors of short-term surgical outcomes. METHODS: A retrospective multicenter cohort study of Minimally-invasivE surgery for oncologic Right ColectomY (MERCY) was conducted on patients who underwent laparoscopic or robotic right colectomy between 2014 and 2020. Classification tree approach was used to describe the extracorporeal (EA) or intracorporeal (IA) anastomosis choice. Mixed-model regressions were used to identify patient- and surgery-related factors predictive of postoperative outcomes. A questionnaire was used to evaluate the surgeons' perspectives. RESULTS: The MERCY database comprised 1870 patients; 87.2% underwent laparoscopy, and 68.1% received an EA. A clear surgical trend was noted, with an increasing rate of IA and robotic procedures after 2017. EA represented 41% of anastomoses in centers equipped with a robotic surgical system. Mixed-model regressions (on 1088 patients) showed that age, sex, BMI, comorbidity, robotics, IA, and conversion to open surgery were predictors of surgical outcomes. In particular, IA was a predictor of a shorter time to regular diet and fewer surgical site infections. Based on the questionnaire, IA was the preferred over EA by 72% of surgeons. CONCLUSION: MIS continues to evolve, with an increasing number of IA being performed in the recent years and when using a robotic surgical system. Understanding the role of predictors of surgical outcomes may help surgeons personalize decision-making among the different MIS options to manage right colon cancer

Conversion to Open Surgery During Minimally Invasive Right Colectomy for Cancer: Results from a Large Multinational European Study

Background: The risk of conversion to open surgery is inevitably present during any minimally invasive colorectal surgical procedure. Conversions have been associated with adverse postoperative and oncologic outcomes. No previous study has evaluated the specific causes and consequences of conversion during a minimally invasive right colectomy (MIS-RC).Materials and Methods: We analyzed the Minimally invasivE surgery for oncologic Right ColectomY (MERCY) study database including patients who underwent laparoscopic or robotic RC because of colon cancer between 2014 and 2020. Descriptive analyses were performed to determine the different reasons for conversion. Uni- and multivariate logistic regressions were run to identify potential variables associated with this outcome. Cox regression analyses were used to evaluate the impact of conversion on tumor recurrence.Results: Over a total of 1574 MIS-RC, 120 (7.6%) were converted to open surgery. The main reasons for conversion were procedural difficulties related to adherences from previous abdominal surgical procedures (39.2%), or owing to large tumor size or infiltration of adjacent structures (26.7%). Only 16.7% of the conversions were caused by intraoperative medical or surgical complications. Converted patients required longer operative times and developed more postoperative complications, both overall (39.2% versus 27.5%; P = .006) and severe ones (13.3% versus 8.3%; P = .061). Male gender (odds ratio [OR] = 1.89 [95% confidence interval: 1.31-2.71]), obesity (OR = 1.99 [1.4-2.83]), prior abdominal surgery (OR = 1.68 [1.19-2.37]), and pT4 cancers (OR = 4.04 [2.86-5.69]) were independently associated with conversion. Conversion to open surgery was not significantly associated with tumor recurrence (hazard ratios = 1.395 [0.724-2.687]).Conclusions: Although conversion to open surgery during MIS-RC for cancer is associated with worsened postoperative outcomes, it seems not to impact on the oncologic prognosis

Impact of operation duration on postoperative outcomes of minimally-invasive right colectomy

Aim: Operation time (OT) is a key operational factor influencing surgical outcomes. The present study aimed to analyse whether OT impacts on short-term outcomes of minimally-invasive right colectomies by assessing the role of surgical approach (robotic [RRC] or laparoscopic right colectomy [LRC]), and type of ileocolic anastomosis (i.e., intracorporal [IA] or extra-corporal anastomosis [EA]). Methods: This was a retrospective analysis of the Minimally-invasivE surgery for oncological Right ColectomY (MERCY) Study Group database, which included adult patients with nonmetastatic right colon adenocarcinoma operated on by oncological RRC or LRC between January 2014 and December 2020. Univariate and multivariate analyses were used. Results: The study sample was composed of 1549 patients who were divided into three groups according to the OT quartiles: (1) First quartile, <135 min (n = 386); (2) Second and third quartiles, 135-199 min (n = 731); and (3) Fourth quartile ≥200 min (n = 432). The majority (62.7%) were LRC-EA, followed by LRC-IA (24.3%), RRC-IA (11.1%), and RRC-EA (1.9%). Independent predictors of an OT ≥ 200 min included male gender, age, obesity, diabetes, use of indocyanine green fluorescence, and IA confection. An OT ≥ 200 min was significantly associated with an increased risk of postoperative noninfective complications (AOR: 1.56; 95% CI: 1.15-2.13; p = 0.004), whereas the surgical approach and the type of anastomosis had no impact on postoperative morbidity. Conclusion: Prolonged OT is independently associated with increased odds of postoperative noninfective complications in oncological minimally-invasive right colectomy

Impact of operation duration on postoperative outcomes of minimally-invasive right colectomy

Aim Operation time (OT) is a key operational factor influencing surgical outcomes. The present study aimed to analyse whether OT impacts on short-term outcomes of minimally-invasive right colectomies by assessing the role of surgical approach (robotic [RRC] or laparoscopic right colectomy [LRC]), and type of ileocolic anastomosis (i.e., intracorporal [IA] or extra-corporal anastomosis [EA]). Methods This was a retrospective analysis of the Minimally-invasivE surgery for oncological Right ColectomY (MERCY) Study Group database, which included adult patients with nonmetastatic right colon adenocarcinoma operated on by oncological RRC or LRC between January 2014 and December 2020. Univariate and multivariate analyses were used. Results The study sample was composed of 1549 patients who were divided into three groups according to the OT quartiles: (1) First quartile, <135 min (n = 386); (2) Second and third quartiles, 135-199 min (n = 731); and (3) Fourth quartile >= 200 min (n = 432). The majority (62.7%) were LRC-EA, followed by LRC-IA (24.3%), RRC-IA (11.1%), and RRC-EA (1.9%). Independent predictors of an OT >= 200 min included male gender, age, obesity, diabetes, use of indocyanine green fluorescence, and IA confection. An OT >= 200 min was significantly associated with an increased risk of postoperative noninfective complications (AOR: 1.56; 95% CI: 1.15-2.13; p = 0.004), whereas the surgical approach and the type of anastomosis had no impact on postoperative morbidity. Conclusion Prolonged OT is independently associated with increased odds of postoperative noninfective complications in oncological minimally-invasive right colectomy