Interlayer Technique Research Articles

COMPARATIVE STUDY OF SURGICAL OUT COME OF INTERLAY TYMPANOPLASTY AND UNDERLAY TYMPANOPLASTY IN TERMS OF HEARING IMPROVEMENT AND GRAFT UPTAKE

Introduction: Perforation of the tympanic membrane primarily results from middle ear infections, trauma or iatrogenic causes. Up to 80% of these perforations heal spontaneously; for the remaining, surgical repair, known as myringoplasty, is usually proposed. The principal indications are recurrent otorrhea, the desire to swim without having to waterproof the ear and to improve conductive hearing loss. Several factors may affect surgical outcome such as the surgical approach (endaural, postaural) and technique (underlay vs. overlay), site of perforation and type of graft utilized. Material &Methods: This study was carried out from January 2018 to October 2019. Detailed history and examination were carried out the patient of Chronic Otitis Media with Inactive mucosal disease in large central perforation. Out of 50 patients, 25 patients were operated by underlay technique and rest 25 patients were operated by interlay tympanoplasty. In both the techniques of myringoplasty post auricular approach and temporalis fascia was used as a graft material and operated under general or local anesthesia. Conclusion: Thus in present study as far as resolution of air bone gap is concerned, Interlay technique showed a statistically better outcome as compared to the underlay group. The findings in present study showed a better graft up take in Interlay method which coupled with a better postoperative air bone gap provided a better overall outcome. Key words: Tympanoplasty , Interlay Tympanoplasty, Underlay Tympanoplasty, CSOM,

A Comparative Study on Endoscopic Underlay versus Interlay Technique of Type I Tympanoplasty

Introduction: Tympanoplasty by underlay method is the commonly employed technique to repair perforated tympanic membrane and is conventionally done using a microscope. Aim of this study was to compare the results of underlay and interlay technique of endoscopic tympanoplasty between two groups. Materials and methods: A total of 100 patients were included in the study, with in a period of two years. All of them underwent type I endoscopic tympanoplasty, 50 patients in group 1 by interlay and 50 patients in group 2 by underlay method. All of whom were followed up for 6 months. Patients were evaluated and compared in terms of graft uptake, improvement in hearing and rate of complications Results: In the present study, Group 1 patients have recorded a graft uptake rate of 100% where as in group 2 it was 94%. 88% of the patients in group 1 and 84 % in group 2 reported a complete ABG closure at the end of 6 month. Conclusion: Endoscopic tympanoplasty, by interlay technique gives a very good success rate both in terms of graft uptake and air-bone gap closure when compared to underlay method. KEYWORDS: endoscopic tympanoplasty, interlay, underlay

Type 1 Tympanoplasty by Interlay Technique for Management of Tympanic Membrane Perforation

Tympanic membrane is the partition between the external ear and middle layer which is a vital component of the human ear. Neglected or maltreated earache, ear discharge and trauma lead to perforation of tympanic membrane. Tympanoplasty is the surgical procedure performed to repair a perforated tympanic membrane, with/without reconstruction of the ossicles, with the aim of preventing reinfection and restoring hearing ability. Type 1 tympanoplasty is the simple closure of the tympanic membrane perforation. To study the outcome of type 1 tympanoplasty operation by interlay technique, a descriptive longitudinal study was conducted among 200 patients in Community Based Medical College Hospital and in private clinics of Mymensingh from January 2012 to December 2021. Our inclusion criteria was population of age ranging from 15 to 55 yrs of both sexes having dry central perforation for at least 6 weeks and exclusion criteria was patient with active stage of chronic suppurative otitis media (CSOM), ossicular discontinuity, sensory neural hearing loss. Data was analyzed by SPSS version 20.0. Prevalence of taking graft was 96.00%. Measured by difference of preoperative air bone gap (ABG) and postoperative ABG of 15 decibel (dB) hearing improvement rate was 90%. Complication was minimal (1%). The complication was infection due to non-compliance with postoperative advice and treatment. Type 1 tympanoplasty done by interlay technique has excellent results both in terms of graft taken and hearing improvement with minimal complications.
 CBMJ 2023 January: Vol. 12 No. 01 P: 67-72

Endoscopic tympanoplasty type I using interlay technique

BackgroundTympanoplasty using the interlay technique has rarely been reported in transcanal endoscopic ear surgery, unlike the underlay technique. This is because many surgeons find it challenging to detach the epithelial layer of the tympanic membrane using only one hand. However, the epithelial layer can be easily detached from the inferior part of the tympanic membrane. Another key point is to actively improve anteroinferior visibility even if the overhang is slight because most perforations and postoperative reperforations are found in the anteroinferior quadrant of the tympanic membrane. We report the application of the interlay technique in endoscopic tympanoplasty type I for tympanic perforations.MethodsWe retrospectively reviewed the medical records of 51 patients who had undergone tympanoplasty using the interlay technique without ossiculoplasty between 2017 and 2020. We then compared the data with those of patients who underwent microscopic surgery (MS) using the underlay technique between 1998 and 2009 (n = 104). No other technique was used in each group during this period. Repair of tympanic membrane perforation and hearing outcomes were assessed for > 1 year postoperatively.ResultsThe perforation sites were limited to the anterior, posterior, and anterior–posterior quadrants in 23, 1, and 27 ears, respectively. Perforations were closed in 50 of the 51 ears (98.0%), and the postoperative hearing was good (average air-bone [A-B] gap was 6.8 ± 5.8 dB). The surgical success rate for the repair of tympanic membrane perforation was not significantly different from the MS group (93.3%, P = 0.15). The average postoperative average A-B gap in the group that underwent the interlay technique was significantly different from that in the MS group (10.1 ± 6.6 dB, P < 0.01).ConclusionThe interlay technique should be considered as one of the treatment methods in endoscopic surgery for tympanic perforations. Further study of the postoperative outcomes of this procedure should be conducted to establish the optimal surgical procedure for tympanic perforations.Trial registration: This study was retrospectively approved by the Institutional Review Board of the Jikei University, Tokyo, Japan (approval number: 32-205 10286).Video abstractEHU69PToR4KkpCPbQtPHKeVideo abstract

A Comparative Study of the Interlay and Underlay Techniques of Tympanoplasty Type І for Management of Tympanic Membrane Perforation

Background: The remaining chronic non healing perforations result in recurrent ear discharge causing great discomfort to the patient and decreased hearing.Objectives: We aimed to assess and compare the results of the underlay and interlay techniques of tympanoplasty type I in cases of medium to large sized dry central tympanic membrane perforation.Patients and methods: : Prospective study was carried out on 54 patients having medium to large sized central tympanic membrane perforation who were divided randomly into two groups.Group I patients underwent for underlay tympanoplasty type I, while group II patients underwent for interlay tympanoplasty type I. Hearing results were assessed by comparing the preoperative and postoperative pure tone audiogram as well as closure of the air-bone gap.Results: In terms of graft uptake 3-months postoperatively, in the underlay group, the success rate was 92.6%, while in the interlay group, the success rate was 96.2%. In terms of hearing improvement at the end of the 3rd month, in the underlay group, 40.8% of the patients had hearing gain from 11-20 dB, while in the interlay group, 66.7% of the patients had hearing gain from 11-20 dB.Conclusion: The success rates for the interlay technique is better than the underlay technique and have been quite promising. Therefore, such technique should be more practiced among the surgeons.

Outcome of underlay versus interlay tympanoplasty in patients with inactive mucosal chronic otitis media with large central perforation: a retrospective comparative study

&lt;p class="abstract"&gt;&lt;strong&gt;Background:&lt;/strong&gt; Aim and objective were to study the outcome of underlay versus interlay tympanoplasty in patients with inactive mucosal chronic otitis media with large central perforations in terms of graft uptake rate and hearing improvement. &lt;/p&gt;&lt;p class="abstract"&gt;&lt;strong&gt;Methods:&lt;/strong&gt; The present study was conducted retrospectively on 110 patients of inactive mucosal chronic otitis media with large central perforation, 55 patients selected from each group undergoing underlay or interlay technique in a tertiary referral hospital, Department of ENT, ESIC Kalaburagi, Karnataka, from February 1 2018 to January 31, 2020. &lt;/p&gt;&lt;p class="abstract"&gt;&lt;strong&gt;Results:&lt;/strong&gt; Total 110 patients were included in the study. Male:female ratio was 1:2.2. The age group in this study ranged from 13-50 years of age. Preoperative mean air bone gap in groups A and B was 30.28±6.62, and 30.18±6.87 dB and postoperative mean air bone gap was 19.44±7.66 and 15.13±6.3 dB. In both the groups a significant mean reduction in air bone gap was observed. Mean reduction was maximum in group B. Statistically, intergroup difference in reduction in air bone gap was highly significant (p&amp;lt;0.001). Graft success rate being 89.09% and 94.54% in underlay (group A) and interlay (group B) respectively.&lt;/p&gt;&lt;p class="abstract"&gt;&lt;strong&gt;Conclusions:&lt;/strong&gt; Interlay is a better technique than underlay in chronic otitis media inactive mucosal disease with large central perforation in terms of hearing improvement and graft uptake. &lt;/p&gt;

A Study of Interlay Grafting in Type 1 Tympanoplasty for Large Central Perforation.

The objective of the study was to study the outcomes of interlay type 1 tympanoplasty in large central perforations in terms of graft uptake, hearing improvement and complications. Study included 150 symptomatic patients having large central perforation in tympanic membrane willing for surgery who later underwent tympanoplasty with or without cortical mastoidectomy. All the patients selected for study, were assessed for subjective and objective evaluation pre-operatively and then post-operatively after 4months. The study was conducted at tertiary health care hospital. Type I tympanoplasty with Interlay technique for large central perforations is superior. The Interlay technique in Type I tympanoplasty has high success both in terms of graft uptake as well as ABG closure. In the view of the advantages it offers, it should be preferred over the other conventional techniques in patients with large central perforations for better results.

Interlay technique type 1 tympanoplasty, an alternative for closing large central tympanic membrane perforation

Background: Type 1 tympanoplasty or myringoplasty is the most frequently performed procedure in the field of otology. Type 1 tympanoplasty is a surgical procedure to repair and only involves the restoration of the perforated tympanic membrane. There are three most accepted methods often used universally, namely underlay, overlay, and interlay. The interlay method is a relatively new method developed in 1992 for closing tympanic membrane perforation. This method has a high success rate of 96%. Objective: To report the success of type 1 tympanoplasty with an interlay method to close large central tympanic membrane perforations at Margono Soekarjo District Hospital. Case Report: Reporting 3 cases of chronic tubotympanic suppurative otitis media with large central tympanic membrane perforation which were repaired by type 1 tympanoplasty using interlay method. Clinical Question: Does interlay method type 1 tympanoplasty performed on large central tympanic membrane perforation provide better result compared with other methods of type 1 tympanoplasty? Review Method: Studying the evidence-based literatures on type 1 tympanoplasty interlay methods through Cochrane, Pubmed, and Google Scholar databases. Based on the inclusion and exclusion criteria, three journals were relevant with the reported cases. Result: All three journals stated that interlay method type 1 tympanoplasty had high success rate in terms of closing the tympanic membrane perforation and diminishing air-bone gap. Conclusion: Type 1 Tympanoplasty interlay method could be used as an alternative for the closure of a large central tympanic membrane perforation.Keywords: Chronic Tubotympanic Suppurative Otitis Media, large central tympanic membrane perforation, interlay tympanoplasty ABSTRAK Latar belakang: Timpanoplasti tipe 1 atau miringoplasti merupakan prosedur di bidang otologi yang paling sering dilakukan. Timpanoplasti tipe 1 merupakan metode pembedahan yang bertujuan untuk memperbaiki, dan terbatas hanya di membran timpani. Terdapat tiga metode yang paling diterima dan sering digunakan secara universal, yaitu underlay, overlay, dan interlay. Metode interlay merupakan metode penambalan perforasi membran timpani yang relatif baru, dikembangkan pada tahun 1992. Metode ini mempunyai keberhasilan yang tinggi yaitu mencapai 96%. Tujuan: Melaporkan keberhasilan timpanoplasti tipe 1 dengan metode interlay untuk penutupan perforasi membran timpani sentral besar di RSUD Margono Soekarjo. Laporan kasus: Dilaporkan 3 kasus otitis media supuratif kronik tipe tubotimpani dengan perforasi sentral besar, yang dilakukan timpanoplasti tipe 1 dengan metode interlay. Pertanyaan klinis: Apakah metode interlay timpanoplasti tipe 1 yang dilakukan pada perforasi membran timpani yang besar, dapat memberikan hasil yang lebih baik daripada metode lain timpanoplasti tipe 1? Telaah literatur: Telaah berbasis bukti mengenai timpanoplasti tipe 1 metode interlay melalui database Cochrane, Pubmed, dan Google Scholar. Berdasarkan kriteria inklusi dan ekslusi didapatkan tiga jurnal yang relevan dengan kasus yang dilaporkan. Hasil: Ketiga jurnal tersebut menyatakan bahwa timpanoplasti tipe 1 metode interlay mempunyai angka keberhasilan yang tinggi dalam hal penutupan perforasi membran timpani maupun mengurangi air-bone gap. Kesimpulan: Timpanoplasti tipe 1 metode interlay dapat digunakan sebagai alternatif untuk penutupan perforasi membran timpani sentral yang besar

Endoscopic interlay tympanoplasty: our experience

&lt;p class="abstract"&gt;&lt;strong&gt;Background:&lt;/strong&gt; Chronic otitis media is treated conventionally by tympanoplasty using a temporalis fascia graft using a microscope, through a post aural approach. The present study comprises of 50 cases of chronic otitis media, which were treated by endoscopic interlay technique of tympanoplasty, combining two novel approaches in otological surgery.&lt;/p&gt;&lt;p class="abstract"&gt;&lt;strong&gt;Methods:&lt;/strong&gt; Total of 50 patients were studied, with in a period of one year at our institution. All of them underwent type I endoscopic tympanoplasty by interlay method. All of whom were followed up for 6 months. Patients were evaluated in terms of graft uptake, improvement in hearing and rate of complications. &lt;/p&gt;&lt;p class="abstract"&gt;&lt;strong&gt;Results:&lt;/strong&gt; In the present study, we have recorded a graft uptake rate of 98%. The mean post operative air bone gap at the end of 6 months was 0.9 dB (p=0.001) which was statistically highly significant.&lt;/p&gt;&lt;p class="abstract"&gt;&lt;strong&gt;Conclusions:&lt;/strong&gt; Endoscopic interlay tympanoplasty is a novel and preferred technique, which could be implemented in all cases of dry chronic otitis media.&lt;/p&gt;

A Randomized Prospective Study on Interlay Vs Underlay of Type I Tympanoplasty in Remote Tertiary Center

Background: Type I tympanoplasty is a surgical technique used to restore the integrity of tympanic membrane as well as improve the hearing in inactive mucosal chronic otitis media. There are two main methods that are underlay and overlay in between both is interlay. The aim of the present study is to analyse and compare the results of the two most commonly used type I tympanoplasty techniques, underlay and the interlay technique in chronic otitis media with mucosal disease in large central perforation, in terms of graft uptake and hearing improvement. Subjects and Methods: This is a randomized prospective study of 100 cases of inactive mucosal chronic otitis media with total or large anterior central perforation between October2017 to September 2019 in Anugarah Narayan Magadh Medical College &amp; Hospital, Gaya. Half had gone through Interlay and half by Underlay technique of Type I Tympanoplasy surgery. Results: The graft uptake rate in this study was 96% and 90% for Interlay and Underlay technique respectively. Postoperatively mean air bone gap maximally reduced in the Interlay technique. Conclusion: The present study showed that Interlay method had better graft uptake rate as well as hearing improvement in total and large anterior central perforation of inactive mucosal chronic otitis media than the Underlay technique.

Introduction of new surface geometry to join Ti-6Al-4V and SS304L by friction welding

PurposeIn friction welding of dissimilar joint method, few material compositions are not possible to weld effectively. For better dissimilar metal joining in friction welding, the interlayer techniques are used by the third metal to increase the diffusion for suitable metal bonding. The interlayer metals are popularly held by coating, foils, sheet and solid rod form. The coating method needs more care for surface preparation with special coating equipment with high workmanship. In case of foil as intermediate metal, more care is neededfor holding between the metal; most of the time this technique has the possibility of failure by peeling off from the contact surface during high speed rotation with pressure during friction generation.Design/methodology/approachIn this investigation, a copper coin was machined to a suitable size (transition fit) to suit the recess inside the SS rod. The mating surfaces of Cu coin, SS rod and Ti alloy were machined, polished to mirror finish and handled in friction welding machine. The purpose of the transition fit between the coin and SS rod is for holding the same intact before the beginning of the process.FindingsSuccessful joint was achieved with good joint strength at less time. Empirical models were established to fin out the joint strength at any given parameter within the range of investigationResearch limitations/implicationsThe models developed can be used only within the range of investigation considered for experimentation.Practical implicationsThe paper includes implications for the development of a method of joining any dissimilar jointsOriginality/valueIn this investigation, a copper coin was machined to a suitable size (transition fit) to suit the recess inside the SS rod. The mating surfaces of Cu coin, SS rod and Ti alloy were machined, polished to mirror finish and handled in friction welding machine. The purpose of the transition fit between the coin and SS rod is for holding the same intact before the beginning of the process.

Interface Microstructure Characteristics of Friction-Welded Joint of Titanium to Stainless Steel with Interlayer

Dissimilar joining between stainless steel and titanium by friction welding enhances the metallurgical compatibility and properties of the interface. The severity of the formation of intermetallic compounds is inhibited up to some extent. However, the complete prevention of the Fe–Ti and Cr–Ti type of intermetallic compounds cannot occur. In this study, the interlayer technique has been applied to develop friction-welded joints between dissimilar materials. Tantalum is one of the candidate materials to act as an interlayer between titanium and stainless steel and can form ample metallurgical compatibility with both of the substrates. The interface between stainless steel and interlayer exhibited the presence of a mixed region. The diffusion of titanium atoms into the interlayer is revealed along with the interface of titanium to an interlayer. The electron probe microanalyzer characterized the diffusion of atoms at interfaces. The microhardness survey unveiled the increasing hardness over the stainless steel and interlayer interface.

PHILOSOPHY AND CONCEPT OF TOTAL ANNULUS EXCISION (TAE): A NOVEL APPROACH FOR TYMPANOPLASTY

Tympanic membrane perforation is a common pathology encountered by an ear surgeon. The surgical repair and reconstruction of these defects of the drumhead has been addressed by two popular techniques - viz., the common and popular underlay technique and the lesser known interlay technique. In underlay technique of tympanoplasty, mucosalization of the graft many a times leads to continuous or intermittent discharging ear despite an intact tympanic membrane - and this has been called the “Red Drum Conundrum”. Total annulus excision (TAE) implies that the entire annulus is removed along with remnant of tympanic membrane during the procedure to surgically reconstruct a diseased membrane. TAE is an essential step of a broader technique of interlay technique. This novel Interlay technique’s basic premise is that - Once the graft is placed, there must not be any mucous membrane lateral to the graft and no epithelium medial to the graft. One very important benefit of TAE is neovascularization around the graft. Total annular excision is a new emerging technique of tympanoplasty as it gives patient a three layered physiologically and anatomically near natural membrane with good vibratory function without possibility of weeping membrane or granular myringitis. Key Words: Annulus, tympanoplasty, interlay, middle ear, tympanic membrane, Myringoplasty

Influence of interlayer technique on microstructure and mechanical properties of Ti/Al cladding plate manufactured via explosive welding

In this study, different series of TA2/5083 cladding plates with and without the 1060 interlayers (0.3 and 0.5 mm thick) were manufactured via explosive welding. From the perspective of dynamics and energy, the perfectly inelastic collision theory and the momentum conservation theory were applied to calculate collision velocity and kinetic energy loss of each layer, thereby analyzing and studying the action mechanism of an interlayer in Ti/Al explosive welding. Microstructural work and mechanical tests were carried out to research the effect of the interlayer technique on the comprehensive properties of TA2/5083 explosive clads. The results indicated that the use of the interlayer technique could significantly reduce the collision velocity and actually divided the total kinetic energy loss of the flyer plate through multiple collision processes, thereby solving the problem of excessive kinetic energy loss in direct welding. The cladding plate manufactured via direct welding presented the planar interfacial morphology where the continue melting layer accompanied by a slender microcrack were observed, while the cladding plates with the interlayers exhibited good quality of bonding without major defects. In addition, the typical microstructures near the TA2/1060 interfaces, such as vortex and melting block, were reported. Mechanical tests of the three cladding plates found that the values of microhardness near the interfaces were increased due to the work hardening in explosive welding. The TA2/5083 cladding plate with a 0.3 mm thick 1060 interlayer had the highest tensile and shear strength, showing the best quality welded joint. The fractographic study indicated that ductile fracture was the main character.

Interlay Technique Tympanoplasty: Surgical Difficulties with Variable Grafts

Perforation of the tympanic membrane is most commonly the result of chronic ear disease. However, it can also result from various forms of trauma, which includes iatrogenic and direct physical injuries, burns, scalds and pressure effects. Most of these perforations heal spontaneously, whereas the remaining long-standing perforations that lead to recurrent ear discharge need tympanoplasty. Objectives: the aim of this study was to evaluate the results of interlay technique of tympanoplasty with respect to graft uptake and hearing status and to compare surgical difficulties between variable grafts. Patients and Methods:A total of 20 Patients included in the study were 6 males and 14 females, their age ranged from 10 years to 50 years presented with dry large central tympanic membrane perforations being inactive for at least one month without treatment were operated by interlay myringoplasty . Results:

Interlay Technique Tympanoplasty: Surgical Difficulties with Variable Grafts

Interlay Technique Tympanoplasty: Surgical Difficulties with Variable Grafts

Interlay versus underlay type 1 tympanoplasty: a comparative study of the techniques in 100 cases

&lt;p class="abstract"&gt;&lt;strong&gt;Background:&lt;/strong&gt; Type 1 tympanoplasty is a surgical technique used to restore the integrity of tympanic membrane as well as to improve hearing level in patients with large central perforations (inactive mucosal chronic otitis media).&lt;/p&gt;&lt;p class="abstract"&gt;&lt;strong&gt;Methods:&lt;/strong&gt; This is a randomized prospective study of 12 month duration from January 2017 to December 2017 in 100 patients of chronic otitis media inactive mucosal type with large central perforation admitted in the E.N.T department at Geetanjali Medical College and Hospital, Udaipur. &lt;/p&gt;&lt;p class="abstract"&gt;&lt;strong&gt;Results:&lt;/strong&gt; The graft uptake rate in the present study was found to be 96% and 90% respectively in interlay and underlay techniques. Post operatively after 12 weeks mean air bone gap was maximum reduced in Interlay tympanoplasty.&lt;/p&gt;&lt;p class="abstract"&gt;&lt;strong&gt;Conclusions:&lt;/strong&gt; The present study showed that Interlay technique had a better graft take rate as well as hearing improvement in large central perforation of chronic otitis media than the underlay technique.&lt;/p&gt;

Interlay myringoplasty: hearing gain and outcomein large central tympanic membrane perforation

Background: Tympanic membrane Perforations primarily results from middle ear infections and myringoplasty is a surgical procedure used to repair the tympanic membrane and to improve hearing. The interlay technique is a newer safe and technique that has shown higher success rates and is considered better than both overlay as well as the underlay techniques. Aims and objectives: To analyze the results of interlay myringoplasty, in terms of graft uptake and hearing improvement in cases of chronic suppurative otitis media with inactive mucosal disease with large central perforation. Materials and Methods: This is a prospective study conducted from August 2015 to January 2018 in 60 patients of chronic suppurative otitis media (CSOM) with large central perforation. All patients underwent interlay myringoplastythrough post aural approach after clinical examination, audiometric tests &amp; routine investigations. Patients were called for regular follow up for 12 weeks. Results:The graft uptake rate in the present study was found to be 93.33%, Pre operatively mean air bone gap was 28.5±6.96 dB and Post operatively after 12 weeks mean air bone gap improved to 15.83±3.37. Conclusion: Interlay myringoplasty with a superiorly based TM flap is an effective technique over conventional methods in terms of both graft uptake as well as hearing improvement in large central perforation.

Longitudinal Study of Type I Interlay Tympanoplasty.

The aim of the present study was to access success rate of tympanoplasty and complications with interlay technique of tympanoplasty. This Longitudinal Prospective study was carried out in the Department of Otorhinolaryngology and Head and Neck Surgery, Era's Lucknow Medical College, Lucknow. 50 patients aged between 10 and 50years of chronic otitis media mucosal type disease with dry ears were selected. Otomicroscopic, tunning fork test, pure tone audiometry were done in all patients. All patients underwent interlay tympanoplasty. Patients were followed up regularly for a minimum period of 1.5years. Successful graft uptake was noted in 48 (96%) cases. Interlay tympanoplasty results in excellent graft uptake and good post operative Air Bone Gap closure.

Tunneling contact IGZO TFTs with reduced saturation voltages

We report a tunneling contact indium-gallium-zinc oxide (IGZO) thin film transistor (TFT) with a graphene interlayer technique in this paper. A Schottky junction is realized between a metal and IGZO with a graphene interlayer, leading to a quantum tunneling of the TFT transport in saturation regions. This tunneling contact enables a significant reduction in the saturation drain voltage Vdsat compared to that of the thermionic emission TFTs, which is usually equal to the gate voltage minus their threshold voltages. Measured temperature independences of the subthreshold swing confirm a transition from the thermionic emission to quantum tunneling transports depending on the gate bias voltages in the proposed device. The tunneling contact TFTs with the graphene interlayer have implications to reduce the power consumptions of certain applications such as the active matrix OLED display.