本文選題：Hf基高介電材料　切入點(diǎn)：溶膠凝膠法　出處：《安徽大學(xué)》2017年碩士論文

【摘要】：隨著超大規(guī)模集成電路的發(fā)展,MOSFET器件的特征尺寸不斷縮小,傳統(tǒng)柵介質(zhì)SiO_2薄膜由于它較低的介電常數(shù)(～3.9)已經(jīng)達(dá)到了它的物理極限。此時(shí),由于量子遂穿效應(yīng),使得柵介質(zhì)層的漏電流急劇增加,導(dǎo)致了器件的可靠性和穩(wěn)定性急劇下降,嚴(yán)重影響器件的使用壽命。近年來,Hf基高介電常數(shù)材料由于具有較高的k值、與Si襯底具有較好的熱穩(wěn)定性和優(yōu)異界面、較大的禁帶寬度以及較大價(jià)帶和導(dǎo)帶偏移,成為替代傳統(tǒng)Si02柵介質(zhì)理想的候選材料,引起了越來越多關(guān)注和研究。薄膜晶體管(TFT)器件作為平板顯示器的核心原件,對(duì)提高平板顯示器的性能起到舉足輕重的作用。而TFT器件的柵絕緣層性能的好壞直接影響著器件的性能。采用高介電常數(shù)的Hf基高介電常數(shù)材料代替?zhèn)鹘y(tǒng)的SiO_2柵介質(zhì),可以有效降低器件的漏電流、減小閾值電壓,可以提高柵極對(duì)源漏極之間電流的調(diào)控作用。目前Hf基高介電薄膜材料的制備方法也有很多,原子層沉積(ALD)是目前業(yè)界制備柵介質(zhì)的主流技術(shù),但ALD技術(shù)需要高真空環(huán)境和薄膜生長(zhǎng)速率非常慢,不利于大規(guī)模的現(xiàn)代化生產(chǎn)。而利用溶膠凝膠法制備Hf基高介電薄膜材料,其成本較低、操作簡(jiǎn)單和材料成分容易控制。因此,利用溶膠凝膠法制備Hf基高k柵介質(zhì)薄膜和器件研究對(duì)集成電路的發(fā)展具有重要意義。溶膠凝膠法由于使用溶液制備薄膜,所以必須進(jìn)行熱處理進(jìn)行固化,而熱處理的溫度對(duì)薄膜的質(zhì)量有著直接影響。基于前期報(bào)道可知,大部分方法制備的鉿基柵介質(zhì)由于低晶化溫度、不太高的介電常數(shù),及高溫下惡化的界面特性阻礙其在MOSFET和TFT中的繼續(xù)應(yīng)用�；谶@些棘手問題,本論文采取Ti、Al等元素?fù)诫s有效改善Hf02薄膜的物性,調(diào)控MOS和TFT器件性能。1、利用溶膠凝膠法制備了 HfO_2薄膜,探究了不同退火溫度對(duì)其結(jié)構(gòu)、光學(xué)和電學(xué)性質(zhì)的影響。實(shí)驗(yàn)結(jié)果表明:不同的退火溫度下HfO_2薄膜具有不同的晶體結(jié)構(gòu),同時(shí)退火溫度有效調(diào)控了 HfO_2薄膜的光學(xué)帶隙;電學(xué)測(cè)試分析表明400℃退火的樣品顯示了優(yōu)化的電學(xué)性能。2、利用溶膠凝膠法制備了 Ti摻雜的HfO_2柵介質(zhì)薄膜,研究了不同的烘烤溫度對(duì)薄膜結(jié)構(gòu)、光學(xué)和電學(xué)性能的影響。烘烤溫度在200℃時(shí),薄膜的電學(xué)性能最好,其介電常數(shù)相對(duì)于HfO_2薄膜有明顯增加。3、利用溶膠凝膠法制備了 Al摻雜的Hf02柵介質(zhì)薄膜,探究了不同的退火溫度對(duì)薄膜光學(xué)和電學(xué)性能的影響。電學(xué)測(cè)試表明:400℃退火的樣品顯示了優(yōu)化的電學(xué)性能,且漏電流有明顯抑制。4、利用溶膠凝膠法制備了 InZnO/HfAlOx薄膜晶體管,通過改變HfAlOx薄膜的退火溫度和絕緣層的厚度,研究絕緣層對(duì)薄膜晶體管性能的影響。器件測(cè)試表明:當(dāng)HfAlOx薄膜在60℃退火溫度時(shí),InZnO/HfAlOx薄膜晶體管展現(xiàn)出較好的性能。
[Abstract]:With the development of VLSI, the characteristic size of MOSFET devices has been shrinking, and the traditional gate dielectric SiO_2 film has reached its physical limit due to its low dielectric constant of 3.9. at this time, due to quantum tunneling effect, The leakage current of the gate dielectric layer increases sharply, which leads to a sharp decrease in the reliability and stability of the device, which seriously affects the service life of the device. In recent years, the high dielectric constant material based on HF has a high k value. It has good thermal stability, excellent interface with Si substrate, large bandgap, large valence band and conduction band offset, and is an ideal candidate material to replace the traditional Si02 gate dielectric. TFT device is the core part of flat panel display. It plays an important role in improving the performance of flat panel display. The performance of gate insulation layer of TFT device directly affects the performance of the device. The high dielectric constant material based on HF is used to replace the traditional SiO_2 gate dielectric. It can effectively reduce the leakage current of the device, reduce the threshold voltage and improve the effect of the gate on the current between the source and drain. At present, there are many methods for the preparation of HF based high dielectric thin films. Atomic layer deposition (ALD) is the main technology for preparing gate dielectric in industry at present, but ALD technology needs high vacuum environment and thin film growth rate is very slow, which is not conducive to large-scale modern production, and the preparation of HF based high dielectric thin films by sol-gel method. Therefore, the preparation of HF based high-k gate dielectric thin films and devices by sol-gel method is of great significance to the development of integrated circuits. Therefore, heat treatment is necessary for curing, and the temperature of heat treatment has a direct effect on the quality of the film. Based on previous reports, it can be seen that most of the Hafnium based gate dielectric prepared by the method is not too high dielectric constant due to its low crystallization temperature. And the deterioration of interfacial properties at high temperature hinders its continued application in MOSFET and TFT. Based on these thorny problems, the physical properties of Hf02 thin films are effectively improved by doping TiOAl and other elements in this paper. The properties of MOS and TFT devices were regulated. HfO_2 thin films were prepared by sol-gel method. The structure of HfO_2 films was investigated at different annealing temperatures. Experimental results show that HfO_2 thin films have different crystal structures at different annealing temperatures and the optical band gap of HfO_2 films is effectively controlled by annealing temperature. Electrical analysis showed that the annealed samples at 400 鈩，

本文編號(hào)：1659100