How to clamp scroll view and container at the end - flutter

Question

I have a single child scroll view inside of stack trying to clamp the bottom container and the scrollview at the end how would be able to achieve that? the scroll view doesn't end before the container at the bottom. Tried changing the physics to clamping but still not working?What am i missing here?
return Stack(
children: [
SingleChildScrollView(
physics: AlwaysScrollableScrollPhysics(),
child: Column(
children: [
Padding(
padding: const EdgeInsets.only(top: 8.0),
child: BiggerBuildProduct(
onPressed: null,
bigImageUrl: product.image[0],
price: product.price.toString(),
name: product.name,
description: product.description,
),
),
Column(
children: <Widget>[
SizedBox(
height: 10,
),
Container(
width: double.infinity,
child: Column(
children: <Widget>[
Container(
decoration: BoxDecoration(
color: Colors.white,
border: Border.all(
color: Colors.grey[200], width: 2.0),
),
height: 50,
child: Padding(
padding:
const EdgeInsets.only(left: 8.0, right: 8.0),
child: Row(
mainAxisAlignment:
MainAxisAlignment.spaceBetween,
children: <Widget>[
Text(
'Product Details',
style: TextStyle(fontSize: 18),
),
CopyButton(
isIOS: isIOS,
product: product,
)
],
),
),
),
Container(
color: Colors.white,
width: MediaQuery.of(context).size.width,
child: Padding(
padding: const EdgeInsets.all(8.0),
child: Text(product.description),
),
),
],
),
),
SizedBox(
height: 10,
),
BuildServiceItems()
],
),
],
)),
Align(
alignment: Alignment.bottomCenter,
child: Container(
padding: EdgeInsets.only(bottom: 20),
height: 100,
color: Colors.white,
width: MediaQuery.of(context).size.width,
child: Row(
mainAxisAlignment: MainAxisAlignment.spaceEvenly,
children: <Widget>[
AppButton(
padding: EdgeInsets.all(0),
isIOS: isIOS,
height: 60,
width: MediaQuery.of(context).size.width * 0.45,
icon: FrinoIcons.f_share,
buttonType: ButtonType.Resell,
text: 'Share Product',
onPressed: () => onImageDownLoad(product),
),
AppButton(
padding: EdgeInsets.all(0),
height: 60,
width: MediaQuery.of(context).size.width * 0.45,
isIOS: isIOS,
icon: FrinoIcons.f_cart_add,
buttonType: ButtonType.DarkRed,
text: 'Add To Cart',
onPressed: () => onAddCartPressed(context, product, isIOS),
),
],
),
),
),
],
);
}