CN112449133A - 一种采用像素内参数调整技术的大动态范围像素结构 - Google Patents
一种采用像素内参数调整技术的大动态范围像素结构 Download PDFInfo
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Abstract
一种采用像素内参数调整技术的大动态范围像素结构，通过浅沟槽隔离栅进行不同像素间的隔离，自钳位光电二极管通过传输门与浮动扩散区连接，浮动扩散区另一端连接复位管和源跟随器，源跟随器通过参数放大开关连接行选管；不同的偏置电压源V1和V2与参数放大开关另一端连接，源跟随器与偏置电压源V1和V2之间的开关分别为K1、K2。该结构是一种以SF晶体管为参量放大器的像素内电荷调整电路，通过改变偏置电压放大或缩小光电信号，从而使得像素的最低可探测信号和最高非饱和信号都得到拓展，实现动态范围的提高。
Description
技术领域
本发明属于CMOS图像传感器领域，尤其涉及一种采用像素内参数调整技术的大动态范围像素结构。
背景技术
CMOS图像传感器被广泛应用于各种应用领域，如安全和监视系统、医学成像、卫星和恒星跟踪。许多应用都要求图像传感器在不同的光照条件下都能有良好的成像能力。
动态范围(DR)定义为最大非饱和输出信号电平和最小可检测输出信号电平的比值，这些要求可通过提高图像传感器的动态范围实现。在传统的4T像素中，由于每次曝光间隔只有很少的光生载流子，低光照时的图像对比度会降低。在高光照条件下，由于过量的载流子使光电二极管很快达到饱和，输出信号容易达到饱和。因此传统的4T像素动态范围很小，很难达到医学、监控等应用领域的要求。
为了突破传统CMOS图像传感器的限制，常采用以下几种方式提高动态范围：采用线性-对数压缩法，即低光下做线性响应，高光照条件下为对数响应，这种方法可以将DR提高几十倍，但是弱光区传感器为非线性响应，而且信噪比和灵敏度很低；饱和探测法，即对饱和后出的电荷积分，但额外的饱和探测电容会降低填充因子；多曝光度法是主流的DR增强方法，它在不改变像素结构的情况下，不同的曝光时间扫描后合成图像，但是它需要额外的存储单元和复杂的读出电路，且易导致图像模糊。
发明内容
针对现有技术存在的问题，本发明一种采用像素内参数调整技术的大动态范围像素结构，是一种以SF晶体管为参量放大器的像素内电荷调整电路，通过改变偏置电压放大或缩小光电信号，从而使得像素的最低可探测信号和最高非饱和信号都得到拓展，实现动态范围的提高。
图1为本发明提出的采用像素内参数调整技术的大动态范围像素结构，该结构中通过浅沟槽隔离栅（101）进行不同像素间的隔离，自钳位光电二极管（102）通过传输门（103）与浮动扩散区（104）连接，浮动扩散区另一端连接复位管（105）和源跟随器（106），源跟随器通过参数放大开关（107）连接行选管（108）；不同的偏置电压源V1（111）和V2（112）与参数放大开关另一端连接，源跟随器与偏置电压源V1和V2之间的开关分别为K1（109）、K2（110）。传输门、复位管、源跟随器、行选管、参数放大开关、开关K1、K2均使用NMOS晶体管实现。传输门由传输信号TG控制，复位管由复位信号RST控制，参数放大开关由SPA信号控制，行选管由行选信号SEL控制，电源选择开关K1、K2由S1、S2信号控制。
自钳位光电二极管由表面嵌位层P+区、N-埋层及P型衬底构成，外界光信号入射到像素表面后被自钳位光电二极管吸收，发生本征吸收，产生光生电子-空穴对，光生电子在势垒区电场作用下吸引至N埋层中；传输门控制自钳位光电二极管的光生电子向浮动扩散区的转移，传输门的栅上加高压时开启，低压时关闭。浮动扩散区为重掺杂N+区，传输门开启后光生电子进入浮动扩散区，浮动扩散区与源跟随器的栅极相连接，参数放大开关被用来短接源跟随器的源极和漏极。
图2是本像素结构的时序图，低光照时将偏置电压V1置为较高电压（1.8V），偏置电压V2置为较低电压（约为1V），t0时刻复位信号RST为1，复位管开启，将所有晶体管复位，并在曝光开始前打开传输门和行选管，将复位信号读至列总线。t1时开始曝光，自钳位光电二极管产生光生电荷，参数放大开关开启，将源跟随器置为存储电容，开关K1开启，将源跟随器的源漏端与较高的偏置电压V1相连接。t2时刻，曝光完成，传输门开启，光生电荷传输至浮动扩散区。t3时刻，关闭传输门，此时行选管未开启，电荷仍存储在源跟随器中，开关K1关闭，开关K2开启，源跟随器源漏端连接的偏置电压变低，在参数放大阶段，参数放大开关开启，行选管打开，通过开关K1和K2，分别用偏置电压V1、V2控制源跟随器的源漏端电位，由于源跟随器的源漏端被参数放大开关短接，此时源跟随器充当存储电容，其电容上的电荷量与浮动扩散区节点电压VFD、偏置电压成正比，当偏置电压发生变化后，由于源跟随器的栅极端浮动，电荷量保持不变，即可得出VFD2/VFD1与V1/V2正相关，实现参数放大的功能；放大阶段之后的t4时刻，关闭参数放大开关，此时源跟随器重新被配置为跟随器功能，缓冲浮动扩散区的输出信号，SEL信号为高，行选管导通，用于将像素信息传输到列上进行进一步处理。浮动扩散区节点-源跟随器栅极电势被放大，其中偏置电压V1、V2的具体大小可根据实际需要的放大倍数调节。；t5时刻变为高光照，此时将偏置电压V1置为较低电压，偏置电压V2置为较高电压，过程仍与上述类似，但输出的VFD被线性缩小。
一种采用像素内参数调整技术的大动态范围像素结构，将源跟随器用于信号放大，由于源跟随器在传统结构中用于缓冲信号，因此它不会牺牲像素的填充因子。源跟随器的源漏电位改变后，耗尽电荷随时间的变化使得源跟随器的电容为耗尽电容。这导致采样的光电二极管信号在浮动扩散区节点或源跟随器栅极放大。入射光子微弱时，放大光电信号，使其大于像素内的固有噪声，提高了灵敏度的同时拓展了像素的最低可探测信号；高光照时，缩小光电信号，降低像素达到饱和点的速度，提高最大非饱和信号。该像素结构在不改变像素尺寸和填充因子的情况下，灵敏度和动态范围均有较大的提高。
附图说明
图1本发明提出的像素结构图；
图2是本发明像素结构的时序图；
图3本像素结构最佳实施方案。
具体实施方式
对浅沟槽隔离层加以改进，可以提高高光照时像素的最大非饱和电流，进一步扩大动态范围。图3说明了浅沟槽隔离层（301）与像素的互连结构，浅沟槽隔离层与自钳位光电二极管区（302）相连，自钳位光电二极管通过传输门（303）连接浮动扩散区（304），浮动扩散区通过高动态范围开关（305）与浅沟槽隔离层连接。浅沟槽隔离层由里到外的材料依次为，薄二氧化硅（306）、多晶硅（307）、薄二氧化硅层（308），两层二氧化硅充当浅沟槽隔离层电容器的上下极板，多晶硅层是浅沟槽隔离层电容器的介质层。低光照时，高动态范围开关关闭，浅沟槽隔离层只有隔离作用；高光照时，高动态范围开关开启，浅沟槽隔离层上极板通过高动态范围开关与浮动扩散区连接，下极板通过衬底与浮动扩散区相连，这相当于浅沟槽隔离层电容与浮动扩散区并联，增加了浮动扩散区的电容上限。
Claims (2)
1.一种采用像素内参数调整技术的大动态范围像素结构，其特征在于：通过浅沟槽隔离栅（101）进行不同像素间的隔离，自钳位光电二极管（102）通过传输门（103）与浮动扩散区（104）连接，浮动扩散区另一端连接复位管（105）和源跟随器（106），源跟随器通过参数放大开关（107）连接行选管（108）；不同的偏置电压源V1（111）和V2（112）与参数放大开关另一端连接，源跟随器与偏置电压源V1和V2之间的开关分别为K1（109）、K2（110）；传输门、复位管、源跟随器、行选管、参数放大开关、开关K1、K2均使用NMOS晶体管实现；传输门由传输信号TG控制，复位管由复位信号RST控制，参数放大开关由SPA信号控制，行选管由行选信号SEL控制，电源选择开关K1、K2由S1、S2信号控制。
2.根据权利要求1所述一种采用像素内参数调整技术的大动态范围像素结构，其特征在于：自钳位光电二极管由表面嵌位层P+区、N-埋层及P型衬底构成，外界光信号入射到像素表面后被自钳位光电二极管吸收，发生本征吸收，产生光生电子-空穴对，光生电子在势垒区电场作用下吸引至N埋层中；传输门控制自钳位光电二极管的光生电子向浮动扩散区的转移，传输门的栅上加高压时开启，低压时关闭；浮动扩散区为重掺杂N+区，传输门开启后光生电子进入浮动扩散区，浮动扩散区与源跟随器的栅极相连接，参数放大开关被用来短接源跟随器的源极和漏极。
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Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20060181626A1 (en) * | 2003-02-07 | 2006-08-17 | Lee Do Y | Optical image receiving device having wide dynamic range |
| JP2008070412A (ja) * | 2006-09-12 | 2008-03-27 | Seiko Epson Corp | 駆動回路、電気光学装置及び電子機器 |
| US8723284B1 (en) * | 2011-02-02 | 2014-05-13 | Aptina Imaging Corporation | Back side illuminated CMOS image sensor with global shutter storage gates stacked on top of pinned photodiodes |
| CN105208302A (zh) * | 2015-09-16 | 2015-12-30 | 上海集成电路研发中心有限公司 | 像素单元结构及其信号采集方法 |
| US20160225803A1 (en) * | 2015-01-29 | 2016-08-04 | Semiconductor Components Industries, Llc | Global shutter image sensor pixels having centralized charge storage regions |
| CN110071128A (zh) * | 2019-03-08 | 2019-07-30 | 天津大学 | 一种高灵敏度大动态范围的像素结构 |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20060181626A1 (en) * | 2003-02-07 | 2006-08-17 | Lee Do Y | Optical image receiving device having wide dynamic range |
| JP2008070412A (ja) * | 2006-09-12 | 2008-03-27 | Seiko Epson Corp | 駆動回路、電気光学装置及び電子機器 |
| US8723284B1 (en) * | 2011-02-02 | 2014-05-13 | Aptina Imaging Corporation | Back side illuminated CMOS image sensor with global shutter storage gates stacked on top of pinned photodiodes |
| US20160225803A1 (en) * | 2015-01-29 | 2016-08-04 | Semiconductor Components Industries, Llc | Global shutter image sensor pixels having centralized charge storage regions |
| CN105208302A (zh) * | 2015-09-16 | 2015-12-30 | 上海集成电路研发中心有限公司 | 像素单元结构及其信号采集方法 |
| CN110071128A (zh) * | 2019-03-08 | 2019-07-30 | 天津大学 | 一种高灵敏度大动态范围的像素结构 |
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